diff --git a/.env b/.env
index 4f2ec8f2..7c9997b5 100644
--- a/.env
+++ b/.env
@@ -56,6 +56,8 @@ APP_BPN_DEBUG=false
 APP_BPN_CONNECTION_TIMEOUT=5
 APP_BPN_STREAM_TIMEOUT=30
 APP_BPN_TOTAL_TIMEOUT=45
+APP_BPN_CONNECT_BASE_URL="http://bpn-connect"
+APP_BPN_CONNECT_API_KEY=
 
 APP_TRAVEL_INFO_BASE_URL="https://www.ep-reisen.de/reiseinformationen/"
 APP_LEGAL_NOTICE_URL="https://www.ep-reisen.de/unternehmen/impressum-skireiseveranstalter/"
diff --git a/.env.test b/.env.test
index 9d631027..85d14697 100644
--- a/.env.test
+++ b/.env.test
@@ -5,3 +5,5 @@ SYMFONY_DEPRECATIONS_HELPER=999999
 PANTHER_APP_ENV=panther
 PANTHER_ERROR_SCREENSHOT_DIR=./var/error-screenshots
 MAILJET_WEBHOOK_BASIC_PASSWORD=secret
+APP_BPN_CONNECT_BASE_URL="http://bpn-connect.test"
+APP_BPN_CONNECT_API_KEY=test
diff --git a/config/packages/framework.yaml b/config/packages/framework.yaml
index 9dd7f6e0..92ce9df5 100644
--- a/config/packages/framework.yaml
+++ b/config/packages/framework.yaml
@@ -14,6 +14,10 @@ framework:
                 policy: sliding_window
                 limit: 5
                 interval: 15 minutes
+            portal_access_request:
+                policy: sliding_window
+                limit: 5
+                interval: 15 minutes
 
     # Enables session support. Note that the session will ONLY be started if you read or write from it.
     # Remove or comment this section to explicitly disable session support.
@@ -34,6 +38,11 @@ framework:
           base_uri: '%env(resolve:APP_CMS_API_BASE_URL)%'
           headers:
             accept: 'text/json'
+        bpn_connect.client:
+          base_uri: '%env(resolve:APP_BPN_CONNECT_BASE_URL)%'
+          headers:
+            accept: 'application/json'
+            X-API-Key: '%env(APP_BPN_CONNECT_API_KEY)%'
 
 when@test:
     framework:
diff --git a/config/packages/zenstruck_schedule.yaml b/config/packages/zenstruck_schedule.yaml
index a02d4828..97ba627e 100644
--- a/config/packages/zenstruck_schedule.yaml
+++ b/config/packages/zenstruck_schedule.yaml
@@ -28,6 +28,10 @@ zenstruck_schedule:
       frequency: "45 1 * * *"
       description: "Removes expired pending newsletter double opt-in requests"
 
+    - task: app:cleanup:guest-invite-accounts
+      frequency: "50 1 * * *"
+      description: "Removes expired dormant guest accounts"
+
     - task: league:oauth2-server:clear-expired-tokens
       frequency: "0 * * * *"
       description: "Removes expired oauth2 tokens hourly"
diff --git a/config/services.yaml b/config/services.yaml
index 6a841594..25ea3a8c 100644
--- a/config/services.yaml
+++ b/config/services.yaml
@@ -100,6 +100,10 @@ services:
                 stream_timeout: '%env(int:APP_BPN_STREAM_TIMEOUT)%'
                 total_timeout: '%env(int:APP_BPN_TOTAL_TIMEOUT)%'
 
+    App\BpnConnect\BpnConnectClient:
+        arguments:
+            $httpClient: '@bpn_connect.client'
+
     App\Twig\AppRuntime:
         arguments:
             $intlExtension: '@twig.extension.intl'
@@ -140,6 +144,7 @@ services:
         arguments:
             $registrationLimiter: '@limiter.registration'
             $passwordResetLimiter: '@limiter.password_reset'
+            $portalAccessRequestLimiter: '@limiter.portal_access_request'
 
     App\Service\TravelDataProvider:
         arguments:
diff --git a/docs/body-dimensions-transition-plan.md b/docs/body-dimensions-transition-plan.md
deleted file mode 100644
index 690e293b..00000000
--- a/docs/body-dimensions-transition-plan.md
+++ /dev/null
@@ -1,120 +0,0 @@
-# Body Dimensions Transition Plan (Stakeholder Draft)
-
-## Goal
-
-Prevent edit-form failures for existing bookings while we transition from legacy body-dimension values to a better long-term field model.
-
-This plan introduces a temporary compatibility phase and keeps sunsetting manual and straightforward.
-
-## Current Problem
-
-- Existing bookings may contain legacy values such as `-148`, `149-157`, or `195+`.
-- Integer-only form fields can fail when these legacy strings are loaded.
-- Result: participant edit forms can crash before submit.
-
-## Proposed Transition Strategy
-
-Use **text input fields** for body dimensions during transition, with explicit server-side format validation.
-
-### Key Decisions
-
-- No gating by booking create date.
-- One unified behavior for all bookings.
-- Accept both legacy and numeric formats during transition.
-- Keep manual sunsetting later (no automated migration switch).
-
-## Functional Scope
-
-Affected fields:
-
-- `height`
-- `weight`
-- `shoeSize`
-
-Affected components:
-
-- `src/Form/BodyDimensionsType.php`
-- `src/Validator/Constraints/ParticipantValidator.php`
-- `src/Form/BookingParticipantType.php` (option passthrough already in place)
-- `config/services.yaml` (ranges remain as validation/config source)
-
-## Validation Rules During Transition
-
-### Accepted formats
-
-- Numeric value: `^\d+$` (e.g. `176`)
-- Legacy lower/open/range tokens:
-  - `^-\d+$` (e.g. `-148`)
-  - `^\d+\+$` (e.g. `195+`)
-  - `^\d+\s*-\s*\d+$` (e.g. `149-157`)
-
-### Requiredness
-
-- Keep existing rule: body dimensions required when rentals are selected.
-
-### Range checks
-
-- Keep current numeric range checks based on `body_dimension_ranges`.
-- Apply range checks only to plain numeric values in transition phase.
-
-## UX/Behavior Expectations
-
-- Existing legacy values render without form initialization errors.
-- New numeric entries are accepted and validated.
-- Invalid free text (e.g. `abc`, `17x`) shows clear validation errors.
-- HTMX refresh behavior remains unchanged.
-
-## Implementation Steps
-
-1. **Form type change**
-   - In `BodyDimensionsType`, replace integer fields with text fields for all three body dimensions.
-   - Keep labels/help text; keep placeholders based on configured ranges.
-
-2. **Validator extension**
-   - Add format validation for all three fields in `ParticipantValidator`.
-   - Keep existing required-when-rentals logic.
-   - Keep existing range validation for numeric values.
-
-3. **Message tuning**
-   - Add one clear message for invalid format.
-   - Retain existing range message for numeric out-of-range values.
-
-4. **Testing and QA**
-   - Validate old bookings with legacy values open/edit successfully.
-   - Validate numeric path (valid and invalid range).
-   - Validate invalid format handling.
-   - Validate rental-required behavior.
-
-## Acceptance Criteria
-
-- No 500 error when editing participants with legacy body-dimension values.
-- Legacy values can be loaded and submitted in transition phase.
-- Numeric values are accepted and range-validated.
-- Invalid text is rejected with a user-facing validation message.
-- Existing participant edit/refresh flows continue to work.
-
-## Risks and Mitigations
-
-- **Risk:** Free-text field semantics are less strict than integer fields.
-  - **Mitigation:** strict server-side regex + range checks.
-
-- **Risk:** Inconsistent data representations during transition.
-  - **Mitigation:** explicit acceptance policy and manual sunset plan.
-
-## Effort Estimate
-
-- Implementation: 0.5 day
-- Validation/message tuning: 0.25 day
-- QA/manual testing: 0.5 day
-- **Total:** ~1 to 1.5 days
-
-## Manual Sunset Plan (Later)
-
-When stakeholders approve end of transition:
-
-1. Replace text fields with final semantic field type(s).
-2. Remove legacy format acceptance from validator.
-3. Keep only final numeric/range validation behavior.
-4. Remove transition-specific tests and copy.
-
-Expected cleanup effort: ~0.25 to 0.5 day.
diff --git a/migrations/Version20260529120000.php b/migrations/Version20260529120000.php
new file mode 100644
index 00000000..1b9b78b1
--- /dev/null
+++ b/migrations/Version20260529120000.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260529120000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Add welcome activation nonce to users';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE user ADD welcome_activation_nonce VARCHAR(64) DEFAULT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE user DROP welcome_activation_nonce');
+    }
+}
diff --git a/migrations/Version20260529130000.php b/migrations/Version20260529130000.php
new file mode 100644
index 00000000..e24a348f
--- /dev/null
+++ b/migrations/Version20260529130000.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260529130000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Add guest invite expiry and activation timestamps to users';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE user ADD welcome_activation_expires_at DATETIME DEFAULT NULL');
+        $this->addSql('ALTER TABLE user ADD welcome_activated_at DATETIME DEFAULT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE user DROP welcome_activated_at');
+        $this->addSql('ALTER TABLE user DROP welcome_activation_expires_at');
+    }
+}
diff --git a/src/BpnConnect/BpnConnectClient.php b/src/BpnConnect/BpnConnectClient.php
new file mode 100644
index 00000000..bf5a94cd
--- /dev/null
+++ b/src/BpnConnect/BpnConnectClient.php
@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\BpnConnect;
+
+use App\BpnConnect\Exception\BpnConnectException;
+use App\BpnConnect\Model\BookingLookupResult;
+use Psr\Log\LoggerInterface;
+use Symfony\Contracts\HttpClient\Exception\ExceptionInterface;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+
+class BpnConnectClient
+{
+    public function __construct(
+        private readonly HttpClientInterface $httpClient,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    public function lookupBooking(string $email, int $bookingNumber): ?BookingLookupResult
+    {
+        $normalizedEmail = mb_strtolower(trim($email));
+
+        try {
+            $response = $this->httpClient->request('GET', 'api/bookings/lookup', [
+                'query' => [
+                    'email' => $normalizedEmail,
+                    'bookingNumber' => $bookingNumber,
+                ],
+            ]);
+
+            if (404 === $response->getStatusCode()) {
+                return null;
+            }
+
+            $data = $response->toArray();
+        } catch (ExceptionInterface $exception) {
+            $this->logger->warning('BPN Connect booking lookup failed', [
+                'email' => $normalizedEmail,
+                'booking_number' => $bookingNumber,
+                'error' => $exception->getMessage(),
+            ]);
+
+            throw new BpnConnectException('Could not lookup booking via BPN Connect.', previous: $exception);
+        }
+
+        return $this->mapBookingLookupResult($data);
+    }
+
+    /**
+     * @param array<string, mixed> $data
+     */
+    private function mapBookingLookupResult(array $data): BookingLookupResult
+    {
+        foreach (['bookingNumber', 'bookingId', 'addressId', 'personId', 'email'] as $requiredField) {
+            if (false === array_key_exists($requiredField, $data) || '' === trim((string) $data[$requiredField])) {
+                throw new BpnConnectException(sprintf('BPN Connect booking lookup response is missing "%s".', $requiredField));
+            }
+        }
+
+        return new BookingLookupResult(
+            bookingNumber: (int) $data['bookingNumber'],
+            bookingId: (int) $data['bookingId'],
+            addressId: (int) $data['addressId'],
+            personId: (int) $data['personId'],
+            email: mb_strtolower(trim((string) $data['email'])),
+            firstName: $this->optionalString($data['firstName'] ?? null),
+            lastName: $this->optionalString($data['lastName'] ?? null),
+        );
+    }
+
+    private function optionalString(mixed $value): ?string
+    {
+        if (null === $value) {
+            return null;
+        }
+
+        $value = trim((string) $value);
+
+        return '' === $value ? null : $value;
+    }
+}
diff --git a/src/BpnConnect/Exception/BpnConnectException.php b/src/BpnConnect/Exception/BpnConnectException.php
new file mode 100644
index 00000000..e30d225e
--- /dev/null
+++ b/src/BpnConnect/Exception/BpnConnectException.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\BpnConnect\Exception;
+
+class BpnConnectException extends \RuntimeException
+{
+}
diff --git a/src/BpnConnect/Model/BookingLookupResult.php b/src/BpnConnect/Model/BookingLookupResult.php
new file mode 100644
index 00000000..238fa2f4
--- /dev/null
+++ b/src/BpnConnect/Model/BookingLookupResult.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\BpnConnect\Model;
+
+class BookingLookupResult
+{
+    public function __construct(
+        public readonly int $bookingNumber,
+        public readonly int $bookingId,
+        public readonly int $addressId,
+        public readonly int $personId,
+        public readonly string $email,
+        public readonly ?string $firstName = null,
+        public readonly ?string $lastName = null,
+    ) {
+    }
+}
diff --git a/src/BusProNet/ApiClient.php b/src/BusProNet/ApiClient.php
index 6b85dffb..a005d604 100644
--- a/src/BusProNet/ApiClient.php
+++ b/src/BusProNet/ApiClient.php
@@ -768,6 +768,11 @@ class ApiClient
         try {
             $this->xmlDump->write($requestId.'_'.$type.'.xml', $body);
         } catch (FilesystemException $e) {
+            $this->logger->warning('Could not write BPN XML dump', [
+                'request_id' => $requestId,
+                'type' => $type,
+                'error' => $e->getMessage(),
+            ]);
         }
     }
 
diff --git a/src/Command/CleanupGuestInviteAccountsCommand.php b/src/Command/CleanupGuestInviteAccountsCommand.php
new file mode 100644
index 00000000..9e9556f5
--- /dev/null
+++ b/src/Command/CleanupGuestInviteAccountsCommand.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Command;
+
+use App\Repository\UserRepository;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand(
+    name: 'app:cleanup:guest-invite-accounts',
+    description: 'Removes expired unactivated guest accounts',
+)]
+class CleanupGuestInviteAccountsCommand extends Command
+{
+    public function __construct(
+        private readonly UserRepository $userRepository,
+        private readonly LoggerInterface $logger,
+    ) {
+        parent::__construct();
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        $threshold = new \DateTimeImmutable();
+
+        $deletedCount = $this->userRepository->deleteExpiredDormantGuestInvites($threshold);
+
+        if (0 === $deletedCount) {
+            $io->success('No expired dormant guest accounts found.');
+
+            return Command::SUCCESS;
+        }
+
+        $this->logger->info('Deleted expired dormant guest accounts', [
+            'count' => $deletedCount,
+            'threshold' => $threshold->format(\DateTimeInterface::ATOM),
+        ]);
+
+        $io->success(sprintf('Deleted %d expired dormant guest account(s).', $deletedCount));
+
+        return Command::SUCCESS;
+    }
+}
diff --git a/src/Controller/Account/GuestAccountActivationController.php b/src/Controller/Account/GuestAccountActivationController.php
new file mode 100644
index 00000000..4a196354
--- /dev/null
+++ b/src/Controller/Account/GuestAccountActivationController.php
@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Account;
+
+use App\Entity\User;
+use App\Exception\GuestAccountActivationExpiredException;
+use App\Service\BookingGuestAccountManager;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\Form\Extension\Core\Type\HiddenType;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+class GuestAccountActivationController extends AbstractController
+{
+    public function __construct(
+        private readonly BookingGuestAccountManager $guestAccountManager,
+        private readonly Security $security,
+    ) {
+    }
+
+    #[Route('/welcome/activate', name: 'app_guest_account_activate', methods: ['GET'])]
+    #[IsGranted('PUBLIC_ACCESS')]
+    public function activate(Request $request): Response
+    {
+        try {
+            $user = $this->guestAccountManager->validateActivationRequest($request);
+        } catch (GuestAccountActivationExpiredException) {
+            return $this->render('account/guest_account_activation_expired.html.twig', [
+                'resendForm' => $this->createResendForm($request->getUri()),
+            ]);
+        }
+
+        $session = $request->getSession();
+        $session->set('_security.main.target_path', $this->generateUrl('app_personal_data'));
+
+        /** @var User $user */
+        $this->security->login($user, null, 'main');
+        $session->set(PersonalDataController::SESSION_FORCE_PASSWORD_CHANGE_KEY, true);
+
+        return $this->redirectToRoute('app_personal_data');
+    }
+
+    #[Route('/welcome/activate/resend', name: 'app_guest_account_activate_resend', methods: ['POST'])]
+    #[IsGranted('PUBLIC_ACCESS')]
+    public function resend(Request $request): Response
+    {
+        $form = $this->createResendForm();
+        $form->handleRequest($request);
+
+        if (false === $form->isSubmitted() || false === $form->isValid()) {
+            return $this->render('account/guest_account_activation_expired.html.twig', [
+                'resendForm' => $form,
+            ]);
+        }
+
+        $activationUrl = (string) $form->get('activationUrl')->getData();
+        $user = $this->guestAccountManager->validateActivationUrlForResend($activationUrl);
+
+        try {
+            $this->guestAccountManager->resendWelcomeEmail($user);
+        } catch (\Throwable) {
+            $this->addFlash('error', 'Die Willkommens-E-Mail konnte gerade nicht erneut gesendet werden. Bitte versuche es später noch einmal.');
+
+            return $this->render('account/guest_account_activation_expired.html.twig', [
+                'resendForm' => $form,
+            ]);
+        }
+
+        $this->addFlash('success', 'Wir haben dir die Willkommens-E-Mail erneut gesendet.');
+
+        return $this->redirectToRoute('app_login');
+    }
+
+    private function createResendForm(string $activationUrl = ''): \Symfony\Component\Form\FormInterface
+    {
+        return $this->createFormBuilder(null, [
+            'action' => $this->generateUrl('app_guest_account_activate_resend'),
+        ])->add('activationUrl', HiddenType::class, [
+            'data' => $activationUrl,
+        ])->getForm();
+    }
+}
diff --git a/src/Controller/Account/PersonalDataController.php b/src/Controller/Account/PersonalDataController.php
index 3237854e..38d9e5a6 100644
--- a/src/Controller/Account/PersonalDataController.php
+++ b/src/Controller/Account/PersonalDataController.php
@@ -37,6 +37,7 @@ class PersonalDataController extends AbstractController
     use HxTrait;
 
     public const string SESSION_REDIRECT_KEY = '_profile_completion_redirect';
+    public const string SESSION_FORCE_PASSWORD_CHANGE_KEY = '_force_password_change';
 
     public function __construct(
         private readonly ApiClient $apiClient,
@@ -68,6 +69,8 @@ class PersonalDataController extends AbstractController
     {
         /** @var User $user */
         $user = $this->getUser();
+        $forcePasswordChange = $request->hasSession()
+            && true === $request->getSession()->get(self::SESSION_FORCE_PASSWORD_CHANGE_KEY, false);
         $email = $user->getEmail();
         $personalData = $this->loadPersonalData($user);
         $newsletterSubscribed = $this->newsletterManager->hasConfirmedOptIn($email);
@@ -75,6 +78,8 @@ class PersonalDataController extends AbstractController
 
         $personalDataForm = $this->createForm(AccountPersonalDataType::class, $personalData, [
             'attr' => ['novalidate' => 'novalidate'],
+            'require_current_password' => false === $forcePasswordChange,
+            'force_password_change' => $forcePasswordChange,
         ]);
         $personalDataForm->handleRequest($request);
 
@@ -86,6 +91,9 @@ class PersonalDataController extends AbstractController
                 if ('' !== $newPassword) {
                     $user->setPassword($this->passwordHasher->hashPassword($user, $newPassword));
                 }
+                if ('' !== $newPassword && true === $forcePasswordChange) {
+                    $user->markWelcomeActivated();
+                }
 
                 // Invalidate cached bookings to ensure edit mode shows updated applicant data
                 $this->dataLoader->invalidateUserBookingCaches($user);
@@ -95,17 +103,21 @@ class PersonalDataController extends AbstractController
                 $user->setProfileComplete($isComplete);
                 $this->entityManager->flush();
 
+                if ('' !== $newPassword && true === $forcePasswordChange && true === $request->hasSession()) {
+                    $request->getSession()->remove(self::SESSION_FORCE_PASSWORD_CHANGE_KEY);
+                }
+
                 $this->addFlash('success', 'Deine persönlichen Daten wurden aktualisiert');
                 $this->logger->info('Updated personal data', [
                     'email' => $user->getEmail(),
                 ]);
 
                 // Handle profile completion redirect
-                $session = $request->getSession();
-                $redirectUrl = $session->get(self::SESSION_REDIRECT_KEY);
+                $session = true === $request->hasSession() ? $request->getSession() : null;
+                $redirectUrl = $session?->get(self::SESSION_REDIRECT_KEY);
 
                 if (null !== $redirectUrl && true === $isComplete) {
-                    $session->remove(self::SESSION_REDIRECT_KEY);
+                    $session?->remove(self::SESSION_REDIRECT_KEY);
 
                     return $this->redirect($redirectUrl);
                 }
@@ -121,6 +133,7 @@ class PersonalDataController extends AbstractController
             'personalDataForm' => $personalDataForm,
             'newsletterSubscribed' => $newsletterSubscribed,
             'newsletterPendingConfirmation' => $newsletterPendingConfirmation,
+            'forcePasswordChange' => $forcePasswordChange,
         ]);
     }
 
diff --git a/src/Controller/Account/PortalAccessRequestController.php b/src/Controller/Account/PortalAccessRequestController.php
new file mode 100644
index 00000000..0ab62bc1
--- /dev/null
+++ b/src/Controller/Account/PortalAccessRequestController.php
@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Account;
+
+use App\Service\BookingGuestAccountManager;
+use App\Service\PublicFormRateLimiter;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+class PortalAccessRequestController extends AbstractController
+{
+    public function __construct(
+        private readonly BookingGuestAccountManager $guestAccountManager,
+        private readonly PublicFormRateLimiter $publicFormRateLimiter,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/portal-access/request', name: 'app_portal_access_request', methods: ['POST'])]
+    #[IsGranted('PUBLIC_ACCESS')]
+    public function request(Request $request): Response
+    {
+        if (false === $this->isCsrfTokenValid('portal_access_request', $request->request->getString('_token'))) {
+            $this->addFlash('error', 'Deine Anfrage konnte gerade nicht verarbeitet werden. Bitte versuche es erneut.');
+
+            return $this->redirectToRoute('app_login');
+        }
+
+        $email = trim($request->request->getString('email'));
+        $bookingNumber = $request->request->getInt('bookingNumber');
+
+        if ('' === $email || false === filter_var($email, FILTER_VALIDATE_EMAIL) || 0 >= $bookingNumber) {
+            $this->addFlash('error', 'Bitte prüfe deine Eingaben.');
+
+            return $this->redirectToRoute('app_login');
+        }
+
+        if (false === $this->publicFormRateLimiter->isPortalAccessAllowed($email, $request)) {
+            $this->addFlash('error', PublicFormRateLimiter::THROTTLED_MESSAGE);
+
+            return $this->render('security/login.html.twig', [
+                'last_username' => '',
+                'error' => null,
+            ], new Response('', Response::HTTP_TOO_MANY_REQUESTS));
+        }
+
+        try {
+            $result = $this->guestAccountManager->requestPortalAccess($email, $bookingNumber);
+        } catch (\Throwable $exception) {
+            $this->logger->warning('Portal access request failed unexpectedly', [
+                'email' => mb_strtolower($email),
+                'booking_number' => $bookingNumber,
+                'error' => $exception->getMessage(),
+            ]);
+
+            $result = BookingGuestAccountManager::PORTAL_ACCESS_NOT_SENT;
+        }
+
+        if (BookingGuestAccountManager::PORTAL_ACCESS_ALREADY_ACTIVE === $result) {
+            $this->addFlash('info', 'Für diese E-Mail-Adresse besteht bereits ein aktiver Portalzugang. Bitte logge dich ein oder nutze „Passwort vergessen“.');
+
+            return $this->redirectToRoute('app_login');
+        }
+
+        $this->addFlash('info', 'Wenn zu deiner Buchung ein Portalzugang möglich ist, haben wir dir eine E-Mail gesendet.');
+
+        return $this->redirectToRoute('app_login');
+    }
+}
diff --git a/src/Controller/Booking/Create/Step4Controller.php b/src/Controller/Booking/Create/Step4Controller.php
index a3e0dec3..f0e9d76f 100644
--- a/src/Controller/Booking/Create/Step4Controller.php
+++ b/src/Controller/Booking/Create/Step4Controller.php
@@ -15,9 +15,11 @@ use App\Exception\TravelNotFoundException;
 use App\Form\BookingCreateStep4Type;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
+use App\Repository\UserRepository;
 use App\Htmx\HxTrait;
 use App\Service\BookingConfigurator;
 use App\Service\BookingCreateContextFactory;
+use App\Service\BookingGuestAccountManager;
 use App\Service\BookingSessionManager;
 use App\Service\NewsletterManager;
 use Psr\Log\LoggerInterface;
@@ -38,9 +40,11 @@ class Step4Controller extends AbstractBookingCreateController
         private readonly BookingConfigurator $bookingService,
         private readonly BookingSessionManager $bookingSessionService,
         private readonly BookingCreateContextFactory $createContextFactory,
+        private readonly BookingGuestAccountManager $guestAccountManager,
         private readonly ApiClient $apiClient,
         private readonly CacheInterface $cache,
         private readonly NewsletterManager $doubleOptInService,
+        private readonly UserRepository $userRepository,
         private readonly LoggerInterface $logger,
     ) {
     }
@@ -64,10 +68,13 @@ class Step4Controller extends AbstractBookingCreateController
 
         $newsletterTargetEmail = $this->resolveNewsletterTargetEmail($bookingCreateDto);
         $newsletterOptInVisible = null !== $newsletterTargetEmail;
+        $guestAccountTargetEmail = $this->resolveGuestAccountTargetEmail($bookingCreateDto);
+        $guestAccountOptInVisible = null !== $guestAccountTargetEmail;
 
         $form = $this->createForm(BookingCreateStep4Type::class, $bookingCreateDto, [
             'show_newsletter_opt_in' => $newsletterOptInVisible,
             'newsletter_target_email' => $newsletterTargetEmail,
+            'show_guest_account_opt_in' => $guestAccountOptInVisible,
         ]);
         $form->handleRequest($request);
 
@@ -125,6 +132,27 @@ class Step4Controller extends AbstractBookingCreateController
                     }
                 }
 
+                $guestAccountOptInSelected = $guestAccountOptInVisible
+                    && $form->has('guestAccountOptIn')
+                    && true === $form->get('guestAccountOptIn')->getData();
+
+                if (true === $guestAccountOptInSelected && null !== $guestAccountTargetEmail) {
+                    try {
+                        $targetParticipant = $this->resolveGuestAccountTargetParticipant($bookingCreateDto);
+                        $this->guestAccountManager->provisionGuestAccountForBooking(
+                            $guestAccountTargetEmail,
+                            (int) $bookingResponse->bookingNumber,
+                            $targetParticipant?->firstName,
+                            $targetParticipant?->lastName,
+                        );
+                    } catch (\Throwable $e) {
+                        $this->logger->warning('Guest account creation failed after booking', [
+                            'email' => $guestAccountTargetEmail,
+                            'error' => $e->getMessage(),
+                        ]);
+                    }
+                }
+
                 // Success: Store booking data in flash for conversion tracking
                 $bookingCreateContext = $this->createContextFactory->createWithParticipantPrices($bookingCreateDto);
                 $this->addFlash('booking_number', $bookingResponse->bookingNumber);
@@ -224,6 +252,36 @@ class Step4Controller extends AbstractBookingCreateController
         return $participant;
     }
 
+    protected function resolveGuestAccountTargetEmail(BookingDto $bookingDto): ?string
+    {
+        if (null !== $this->getUser()) {
+            return null;
+        }
+
+        $participant = $bookingDto->participants[0] ?? null;
+        $email = $participant?->email;
+
+        if (null === $email || '' === trim($email)) {
+            return null;
+        }
+
+        $normalizedEmail = mb_strtolower(trim($email));
+        if (false === filter_var($normalizedEmail, FILTER_VALIDATE_EMAIL)) {
+            return null;
+        }
+
+        if (null !== $this->userRepository->findOneByNormalizedEmail($normalizedEmail)) {
+            return null;
+        }
+
+        return $normalizedEmail;
+    }
+
+    private function resolveGuestAccountTargetParticipant(BookingDto $bookingDto): ?ParticipantDto
+    {
+        return $this->resolveNewsletterTargetParticipant($bookingDto);
+    }
+
     /**
      * Clears travel data and availability cache after successful booking.
      */
diff --git a/src/Entity/User.php b/src/Entity/User.php
index 9d1a8039..8cf323e0 100644
--- a/src/Entity/User.php
+++ b/src/Entity/User.php
@@ -51,6 +51,15 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
     #[ORM\Column(type: 'string', length: 64, nullable: true)]
     private ?string $passwordResetNonce = null;
 
+    #[ORM\Column(type: 'string', length: 64, nullable: true)]
+    private ?string $welcomeActivationNonce = null;
+
+    #[ORM\Column(type: 'datetime_immutable', nullable: true)]
+    private ?\DateTimeImmutable $welcomeActivationExpiresAt = null;
+
+    #[ORM\Column(type: 'datetime_immutable', nullable: true)]
+    private ?\DateTimeImmutable $welcomeActivatedAt = null;
+
     public function __construct(string $email)
     {
         $this->email = self::normalizeEmail($email);
@@ -202,6 +211,78 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
         return $this;
     }
 
+    public function getWelcomeActivationNonce(): ?string
+    {
+        return $this->welcomeActivationNonce;
+    }
+
+    public function setWelcomeActivationNonce(?string $welcomeActivationNonce): static
+    {
+        $this->welcomeActivationNonce = $welcomeActivationNonce;
+
+        return $this;
+    }
+
+    public function getWelcomeActivationExpiresAt(): ?\DateTimeImmutable
+    {
+        return $this->welcomeActivationExpiresAt;
+    }
+
+    public function setWelcomeActivationExpiresAt(?\DateTimeImmutable $welcomeActivationExpiresAt): static
+    {
+        $this->welcomeActivationExpiresAt = $welcomeActivationExpiresAt;
+
+        return $this;
+    }
+
+    public function getWelcomeActivatedAt(): ?\DateTimeImmutable
+    {
+        return $this->welcomeActivatedAt;
+    }
+
+    public function setWelcomeActivatedAt(?\DateTimeImmutable $welcomeActivatedAt): static
+    {
+        $this->welcomeActivatedAt = $welcomeActivatedAt;
+
+        return $this;
+    }
+
+    public function isWelcomeActivationPending(): bool
+    {
+        if (null !== $this->welcomeActivatedAt) {
+            return false;
+        }
+
+        if (null === $this->welcomeActivationNonce || null === $this->welcomeActivationExpiresAt) {
+            return false;
+        }
+
+        return $this->welcomeActivationExpiresAt > new \DateTimeImmutable();
+    }
+
+    public function hasPendingWelcomeInvite(): bool
+    {
+        return null === $this->welcomeActivatedAt && null !== $this->welcomeActivationNonce;
+    }
+
+    public function markWelcomeActivationPending(string $nonce, \DateTimeImmutable $expiresAt): static
+    {
+        $this->welcomeActivationNonce = $nonce;
+        $this->welcomeActivationExpiresAt = $expiresAt;
+        $this->welcomeActivatedAt = null;
+
+        return $this;
+    }
+
+    public function markWelcomeActivated(?\DateTimeImmutable $now = null): static
+    {
+        $this->welcomeActivatedAt = $now ?? new \DateTimeImmutable();
+        $this->welcomeActivationNonce = null;
+        $this->welcomeActivationExpiresAt = null;
+
+        return $this;
+    }
+
     public function eraseCredentials(): void
     {
     }
diff --git a/src/EventListener/ForcePasswordChangeRedirectListener.php b/src/EventListener/ForcePasswordChangeRedirectListener.php
new file mode 100644
index 00000000..2d143a52
--- /dev/null
+++ b/src/EventListener/ForcePasswordChangeRedirectListener.php
@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\EventListener;
+
+use App\Controller\Account\PersonalDataController;
+use App\Entity\User;
+use App\Htmx\HxRedirectResponse;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
+
+class ForcePasswordChangeRedirectListener implements EventSubscriberInterface
+{
+    public function __construct(
+        private readonly Security $security,
+        private readonly UrlGeneratorInterface $urlGenerator,
+    ) {
+    }
+
+    public static function getSubscribedEvents(): array
+    {
+        return [
+            KernelEvents::REQUEST => ['onKernelRequest', 0],
+        ];
+    }
+
+    public function onKernelRequest(RequestEvent $event): void
+    {
+        if (false === $event->isMainRequest()) {
+            return;
+        }
+
+        $request = $event->getRequest();
+        if (false === $request->hasSession()) {
+            return;
+        }
+
+        $session = $request->getSession();
+        if (false === $session->get(PersonalDataController::SESSION_FORCE_PASSWORD_CHANGE_KEY, false)) {
+            return;
+        }
+
+        /** @var User|null $user */
+        $user = $this->security->getUser();
+        if (false === $user instanceof User) {
+            return;
+        }
+
+        $route = (string) $request->attributes->get('_route', '');
+        if (in_array($route, ['app_personal_data', 'app_logout'], true)) {
+            return;
+        }
+
+        $targetUrl = $this->urlGenerator->generate('app_personal_data');
+        if (true === $request->headers->has('HX-Request')) {
+            $event->setResponse(new HxRedirectResponse($targetUrl));
+
+            return;
+        }
+
+        $event->setResponse(new RedirectResponse($targetUrl, Response::HTTP_FOUND));
+    }
+}
diff --git a/src/Exception/GuestAccountActivationExpiredException.php b/src/Exception/GuestAccountActivationExpiredException.php
new file mode 100644
index 00000000..660a139e
--- /dev/null
+++ b/src/Exception/GuestAccountActivationExpiredException.php
@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Exception;
+
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+class GuestAccountActivationExpiredException extends NotFoundHttpException
+{
+}
diff --git a/src/Form/AccountPersonalDataType.php b/src/Form/AccountPersonalDataType.php
index 42eaad65..132f0db3 100644
--- a/src/Form/AccountPersonalDataType.php
+++ b/src/Form/AccountPersonalDataType.php
@@ -26,24 +26,6 @@ class AccountPersonalDataType extends AbstractType
                 'label' => false,
                 'inherit_data' => true,
             ])
-            ->add('currentPassword', PasswordType::class, [
-                'label' => 'Aktuelles Passwort',
-                'mapped' => false,
-                'required' => false,
-                'attr' => [
-                    'autocomplete' => 'current-password',
-                ],
-                'constraints' => [
-                    new Sequentially([
-                        new NotBlank([
-                            'message' => 'Bitte angeben',
-                        ]),
-                        new UserPassword([
-                            'message' => 'Das aktuelle Passwort ist nicht korrekt.',
-                        ]),
-                    ], groups: ['password_change']),
-                ],
-            ])
             ->add('newPassword', RepeatedType::class, [
                 'type' => PasswordType::class,
                 'mapped' => false,
@@ -82,27 +64,53 @@ class AccountPersonalDataType extends AbstractType
                 ],
             ])
         ;
+
+        if (true === $options['require_current_password']) {
+            $builder->add('currentPassword', PasswordType::class, [
+                'label' => 'Aktuelles Passwort',
+                'mapped' => false,
+                'required' => false,
+                'attr' => [
+                    'autocomplete' => 'current-password',
+                ],
+                'constraints' => [
+                    new Sequentially([
+                        new NotBlank([
+                            'message' => 'Bitte angeben',
+                        ]),
+                        new UserPassword([
+                            'message' => 'Das aktuelle Passwort ist nicht korrekt.',
+                        ]),
+                    ], groups: ['password_change']),
+                ],
+            ]);
+        }
     }
 
     public function configureOptions(OptionsResolver $resolver): void
     {
         $resolver->setDefaults([
             'data_class' => PersonalData::class,
+            'require_current_password' => true,
+            'force_password_change' => false,
             'validation_groups' => function (FormInterface $form): array {
                 $groups = ['Default', 'personal_data'];
 
-                if ($this->isPasswordSectionUsed($form)) {
+                if (true === $form->getConfig()->getOption('force_password_change') || $this->isPasswordSectionUsed($form)) {
                     $groups[] = 'password_change';
                 }
 
                 return $groups;
             },
         ]);
+
+        $resolver->setAllowedTypes('require_current_password', 'bool');
+        $resolver->setAllowedTypes('force_password_change', 'bool');
     }
 
     private function isPasswordSectionUsed(FormInterface $form): bool
     {
-        return '' !== (string) $form->get('currentPassword')->getData()
+        return (true === $form->has('currentPassword') && '' !== (string) $form->get('currentPassword')->getData())
             || '' !== (string) $form->get('newPassword')->getData();
     }
 }
diff --git a/src/Form/BookingCreateStep4Type.php b/src/Form/BookingCreateStep4Type.php
index ac03e51e..23840a06 100644
--- a/src/Form/BookingCreateStep4Type.php
+++ b/src/Form/BookingCreateStep4Type.php
@@ -44,6 +44,14 @@ class BookingCreateStep4Type extends AbstractType
             ]);
         }
 
+        if (true === $options['show_guest_account_opt_in']) {
+            $builder->add('guestAccountOptIn', CheckboxType::class, [
+                'label' => 'Benutzeraccount in MyE&P anlegen',
+                'mapped' => false,
+                'required' => false,
+            ]);
+        }
+
         $builder
             ->add('confirmationAccepted', CheckboxType::class, [
                 'label' => 'Ich bestätige, dass alle Angaben korrekt sind und möchte verbindlich buchen.',
@@ -73,9 +81,11 @@ class BookingCreateStep4Type extends AbstractType
             'data_class' => BookingDto::class,
             'show_newsletter_opt_in' => false,
             'newsletter_target_email' => null,
+            'show_guest_account_opt_in' => false,
         ]);
 
         $resolver->setAllowedTypes('show_newsletter_opt_in', 'bool');
         $resolver->setAllowedTypes('newsletter_target_email', ['null', 'string']);
+        $resolver->setAllowedTypes('show_guest_account_opt_in', 'bool');
     }
 }
diff --git a/src/Repository/UserRepository.php b/src/Repository/UserRepository.php
index 2be7c051..eeee5fc4 100644
--- a/src/Repository/UserRepository.php
+++ b/src/Repository/UserRepository.php
@@ -26,4 +26,16 @@ class UserRepository extends ServiceEntityRepository
             ->getQuery()
             ->getOneOrNullResult();
     }
+
+    public function deleteExpiredDormantGuestInvites(\DateTimeImmutable $threshold): int
+    {
+        return (int) $this->createQueryBuilder('u')
+            ->delete()
+            ->where('u.welcomeActivatedAt IS NULL')
+            ->andWhere('u.welcomeActivationExpiresAt IS NOT NULL')
+            ->andWhere('u.welcomeActivationExpiresAt <= :threshold')
+            ->setParameter('threshold', $threshold)
+            ->getQuery()
+            ->execute();
+    }
 }
diff --git a/src/Service/BookingGuestAccountManager.php b/src/Service/BookingGuestAccountManager.php
new file mode 100644
index 00000000..52c18bf5
--- /dev/null
+++ b/src/Service/BookingGuestAccountManager.php
@@ -0,0 +1,351 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+use App\BpnConnect\BpnConnectClient;
+use App\BpnConnect\Exception\BpnConnectException;
+use App\BpnConnect\Model\BookingLookupResult;
+use App\Email\Mailer;
+use App\Entity\User;
+use App\Exception\GuestAccountActivationExpiredException;
+use App\Repository\UserRepository;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\UriSigner;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\PasswordHasher\Hasher\UserPasswordHasherInterface;
+use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
+use function Symfony\Component\String\u;
+
+class BookingGuestAccountManager
+{
+    public const string PORTAL_ACCESS_SENT = 'sent';
+    public const string PORTAL_ACCESS_ALREADY_ACTIVE = 'already_active';
+    public const string PORTAL_ACCESS_NOT_SENT = 'not_sent';
+
+    private const int ACTIVATION_TTL_SECONDS = 3600;
+    private const string WELCOME_EMAIL_SUBJECT = 'Dein MyE&P Konto ist bereit';
+    private const string WELCOME_EMAIL_TEMPLATE = 'email/booking_guest_account_welcome.html.twig';
+
+    public function __construct(
+        private readonly BpnConnectClient $bpnConnectClient,
+        private readonly UserRepository $userRepository,
+        private readonly EntityManagerInterface $entityManager,
+        private readonly UserBootstrapper $userBootstrapper,
+        private readonly UserPasswordHasherInterface $passwordHasher,
+        private readonly UrlGeneratorInterface $urlGenerator,
+        private readonly UriSigner $uriSigner,
+        private readonly Mailer $mailer,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    public function provisionGuestAccount(
+        string $email,
+        ?string $firstName = null,
+        ?string $lastName = null,
+        ?int $addressId = null,
+        ?int $personId = null,
+    ): bool
+    {
+        $normalizedEmail = $this->normalizeEmail($email);
+
+        if ('' === $normalizedEmail || false === filter_var($normalizedEmail, FILTER_VALIDATE_EMAIL)) {
+            throw new \InvalidArgumentException('Invalid email for guest account provisioning.');
+        }
+
+        if (null !== $this->userRepository->findOneByNormalizedEmail($normalizedEmail)) {
+            return false;
+        }
+
+        $user = new User($normalizedEmail);
+        $plainPassword = $this->generateInitialPassword();
+        $passwordHash = $this->passwordHasher->hashPassword($user, $plainPassword);
+        $activationNonce = $this->generateNonce();
+        $activationExpiresAt = $this->createActivationExpiry();
+
+        $this->userBootstrapper->bootstrap(
+            $user,
+            $passwordHash,
+            $addressId,
+            $personId,
+            ['ROLE_CUSTOMER'],
+            [],
+            true,
+        );
+        $user->markWelcomeActivationPending($activationNonce, $activationExpiresAt);
+
+        $this->entityManager->persist($user);
+        $this->entityManager->flush();
+
+        $this->sendWelcomeEmail(
+            $normalizedEmail,
+            $this->buildActivationUrl($normalizedEmail, $activationNonce, $activationExpiresAt),
+            $firstName,
+            $lastName,
+        );
+
+        $this->logger->info('Created guest account after booking', [
+            'email' => $normalizedEmail,
+        ]);
+
+        return true;
+    }
+
+    public function provisionGuestAccountForBooking(
+        string $email,
+        int $bookingNumber,
+        ?string $firstName = null,
+        ?string $lastName = null,
+    ): bool {
+        $normalizedEmail = $this->normalizeEmail($email);
+
+        if ('' === $normalizedEmail || false === filter_var($normalizedEmail, FILTER_VALIDATE_EMAIL) || 0 >= $bookingNumber) {
+            throw new \InvalidArgumentException('Invalid booking guest account provisioning input.');
+        }
+
+        $booking = $this->bpnConnectClient->lookupBooking($normalizedEmail, $bookingNumber);
+        if (null === $booking || false === $this->bookingMatches($booking, $normalizedEmail, $bookingNumber)) {
+            throw new BpnConnectException('Could not resolve matching booking details for guest account provisioning.');
+        }
+
+        return $this->provisionGuestAccount(
+            $normalizedEmail,
+            $firstName ?? $booking->firstName,
+            $lastName ?? $booking->lastName,
+            $booking->addressId,
+            $booking->personId,
+        );
+    }
+
+    public function requestPortalAccess(string $email, int $bookingNumber): string
+    {
+        $normalizedEmail = $this->normalizeEmail($email);
+
+        if ('' === $normalizedEmail || false === filter_var($normalizedEmail, FILTER_VALIDATE_EMAIL) || 0 >= $bookingNumber) {
+            $this->logger->warning('Rejected portal access request with invalid input', [
+                'email' => $normalizedEmail,
+                'booking_number' => $bookingNumber,
+            ]);
+
+            return self::PORTAL_ACCESS_NOT_SENT;
+        }
+
+        $user = $this->userRepository->findOneByNormalizedEmail($normalizedEmail);
+
+        try {
+            $booking = $this->bpnConnectClient->lookupBooking($normalizedEmail, $bookingNumber);
+        } catch (BpnConnectException $exception) {
+            $this->logger->warning('Could not verify portal access booking against BPN Connect', [
+                'email' => $normalizedEmail,
+                'booking_number' => $bookingNumber,
+                'error' => $exception->getMessage(),
+            ]);
+
+            return self::PORTAL_ACCESS_NOT_SENT;
+        }
+
+        if (null === $booking) {
+            $this->logger->warning('Portal access booking lookup returned no result', [
+                'email' => $normalizedEmail,
+                'booking_number' => $bookingNumber,
+            ]);
+
+            return self::PORTAL_ACCESS_NOT_SENT;
+        }
+
+        if (false === $this->bookingMatches($booking, $normalizedEmail, $bookingNumber)) {
+            $this->logger->warning('Portal access booking verification failed', [
+                'email' => $normalizedEmail,
+                'booking_number' => $bookingNumber,
+                'booking_email' => $booking->email,
+                'booking_response_number' => $booking->bookingNumber,
+            ]);
+
+            return self::PORTAL_ACCESS_NOT_SENT;
+        }
+
+        try {
+            if (null === $user) {
+                $this->provisionGuestAccount(
+                    $normalizedEmail,
+                    $booking->firstName,
+                    $booking->lastName,
+                    $booking->addressId,
+                    $booking->personId,
+                );
+            } elseif (false === $user->hasPendingWelcomeInvite()) {
+                $this->logger->info('Portal access requested for already activated account', [
+                    'email' => $normalizedEmail,
+                    'booking_number' => $bookingNumber,
+                ]);
+
+                return self::PORTAL_ACCESS_ALREADY_ACTIVE;
+            } else {
+                $this->resendWelcomeEmail($user, $booking->firstName, $booking->lastName);
+            }
+        } catch (\Throwable $exception) {
+            $this->logger->error('Portal access request could not send welcome email', [
+                'email' => $normalizedEmail,
+                'booking_number' => $bookingNumber,
+                'error' => $exception->getMessage(),
+            ]);
+
+            return self::PORTAL_ACCESS_NOT_SENT;
+        }
+
+        return self::PORTAL_ACCESS_SENT;
+    }
+
+    public function validateActivationRequest(Request $request): User
+    {
+        return $this->resolveActivationRequest($request, false);
+    }
+
+    public function validateActivationRequestForResend(Request $request): User
+    {
+        return $this->resolveActivationRequest($request, true);
+    }
+
+    public function validateActivationUrlForResend(string $activationUrl): User
+    {
+        return $this->resolveActivationRequest(Request::create($activationUrl, 'GET'), true);
+    }
+
+    public function resendWelcomeEmail(User $user, ?string $firstName = null, ?string $lastName = null): void
+    {
+        $previousNonce = $user->getWelcomeActivationNonce();
+        $previousExpiresAt = $user->getWelcomeActivationExpiresAt();
+        $newNonce = $this->generateNonce();
+        $normalizedEmail = $this->normalizeEmail($user->getEmail());
+        $newExpiresAt = $this->createActivationExpiry();
+
+        $user->markWelcomeActivationPending($newNonce, $newExpiresAt);
+        $this->entityManager->flush();
+
+        try {
+            $this->sendWelcomeEmail(
+                $normalizedEmail,
+                $this->buildActivationUrl($normalizedEmail, $newNonce, $newExpiresAt),
+                $firstName,
+                $lastName,
+            );
+        } catch (\Throwable $exception) {
+            $user->setWelcomeActivationNonce($previousNonce);
+            $user->setWelcomeActivationExpiresAt($previousExpiresAt);
+            $this->entityManager->flush();
+
+            $this->logger->error('Could not resend guest account welcome email', [
+                'email' => $normalizedEmail,
+                'error' => $exception->getMessage(),
+            ]);
+
+            throw $exception;
+        }
+
+        $this->logger->info('Resent guest account welcome email', [
+            'email' => $normalizedEmail,
+        ]);
+    }
+
+    private function resolveActivationRequest(Request $request, bool $allowExpired): User
+    {
+        if (false === $this->uriSigner->checkRequest($request)) {
+            throw new NotFoundHttpException();
+        }
+
+        $expires = $request->query->getInt('expires');
+        if (0 >= $expires || $expires < time()) {
+            if (false === $allowExpired) {
+                throw new GuestAccountActivationExpiredException();
+            }
+        }
+
+        $email = $this->normalizeEmail($request->query->getString('email'));
+        $nonce = trim($request->query->getString('nonce'));
+
+        if ('' === $email || '' === $nonce) {
+            throw new NotFoundHttpException();
+        }
+
+        $user = $this->userRepository->findOneByNormalizedEmail($email);
+        if (null === $user || null === $user->getWelcomeActivationNonce() || false === hash_equals($user->getWelcomeActivationNonce(), $nonce)) {
+            throw new NotFoundHttpException();
+        }
+
+        return $user;
+    }
+
+    public function consumeActivation(User $user): void
+    {
+        $user->markWelcomeActivated();
+        $this->entityManager->flush();
+    }
+
+    private function buildActivationUrl(string $normalizedEmail, string $nonce, \DateTimeImmutable $expiresAt): string
+    {
+        $url = $this->urlGenerator->generate('app_guest_account_activate', [
+            'email' => $normalizedEmail,
+            'nonce' => $nonce,
+            'expires' => $expiresAt->getTimestamp(),
+        ], UrlGeneratorInterface::ABSOLUTE_URL);
+
+        return $this->uriSigner->sign($url);
+    }
+
+    private function createActivationExpiry(): \DateTimeImmutable
+    {
+        return new \DateTimeImmutable(sprintf('+%d seconds', self::ACTIVATION_TTL_SECONDS));
+    }
+
+    private function bookingMatches(BookingLookupResult $booking, string $normalizedEmail, int $bookingNumber): bool
+    {
+        return $bookingNumber === $booking->bookingNumber
+            && $normalizedEmail === $this->normalizeEmail($booking->email);
+    }
+
+    private function sendWelcomeEmail(string $normalizedEmail, string $activationUrl, ?string $firstName, ?string $lastName): void
+    {
+        $this->mailer->createAndSendEmail(
+            [
+                'activationUrl' => $activationUrl,
+                'firstName' => $this->normalizeName($firstName),
+                'lastName' => $this->normalizeName($lastName),
+            ],
+            [
+                'to' => $normalizedEmail,
+                'subject' => self::WELCOME_EMAIL_SUBJECT,
+                'template' => self::WELCOME_EMAIL_TEMPLATE,
+            ],
+        );
+    }
+
+    private function normalizeEmail(string $email): string
+    {
+        return u($email)->trim()->lower()->toString();
+    }
+
+    private function normalizeName(?string $value): ?string
+    {
+        if (null === $value) {
+            return null;
+        }
+
+        $trimmed = trim($value);
+
+        return '' === $trimmed ? null : $trimmed;
+    }
+
+    private function generateNonce(): string
+    {
+        return bin2hex(random_bytes(32));
+    }
+
+    private function generateInitialPassword(): string
+    {
+        return bin2hex(random_bytes(24));
+    }
+}
diff --git a/src/Service/PasswordResetManager.php b/src/Service/PasswordResetManager.php
index d0a91eea..0fef0ca0 100644
--- a/src/Service/PasswordResetManager.php
+++ b/src/Service/PasswordResetManager.php
@@ -107,6 +107,9 @@ class PasswordResetManager
     {
         $user->setPassword($this->passwordHasher->hashPassword($user, $plainPassword));
         $user->setPasswordResetNonce($this->generateNonce());
+        if (true === $user->hasPendingWelcomeInvite()) {
+            $user->markWelcomeActivated();
+        }
 
         $this->entityManager->flush();
 
diff --git a/src/Service/PublicFormRateLimiter.php b/src/Service/PublicFormRateLimiter.php
index 39fd8b84..7f2b57a6 100644
--- a/src/Service/PublicFormRateLimiter.php
+++ b/src/Service/PublicFormRateLimiter.php
@@ -14,6 +14,7 @@ class PublicFormRateLimiter
     public function __construct(
         private readonly RateLimiterFactory $registrationLimiter,
         private readonly RateLimiterFactory $passwordResetLimiter,
+        private readonly RateLimiterFactory $portalAccessRequestLimiter,
     ) {
     }
 
@@ -27,6 +28,11 @@ class PublicFormRateLimiter
         return $this->consume($this->passwordResetLimiter, $email, $request);
     }
 
+    public function isPortalAccessAllowed(string $email, Request $request): bool
+    {
+        return $this->consume($this->portalAccessRequestLimiter, $email, $request);
+    }
+
     public function createBucketKey(string $email, ?string $clientIp): string
     {
         return hash('sha256', $this->normalizeEmail($email).'|'.($clientIp ?? 'unknown'));
diff --git a/templates/account/guest_account_activation_expired.html.twig b/templates/account/guest_account_activation_expired.html.twig
new file mode 100644
index 00000000..8292f656
--- /dev/null
+++ b/templates/account/guest_account_activation_expired.html.twig
@@ -0,0 +1,30 @@
+{% extends 'layout.html.twig' %}
+
+{% block content %}
+    <div class="grid grid-cols-1 md:grid-cols-2 gap-8 px-4 lg:px-8 py-8 lg:py-16">
+        <div>
+            <h1 class="text-white uppercase pb-4 mb-8 border-b border-primary-bg/40">
+                Link<br>
+                abgelaufen
+            </h1>
+            {% include '_partials/_flashes.html.twig' %}
+            <div class="pb-4">
+                <p class="mb-4 text-white">
+                    Der Aktivierungslink ist leider abgelaufen. Du kannst dir die Willkommens-E-Mail noch einmal
+                    zusenden lassen.
+                </p>
+                {{ form_start(resendForm) }}
+                <button type="submit" class="button button--primary">
+                    Willkommens-E-Mail erneut senden
+                </button>
+                {{ form_rest(resendForm) }}
+                {{ form_end(resendForm) }}
+            </div>
+            <div class="flex space-x-2">
+                <a href="{{ path('app_login') }}" class="text-white underline">
+                    Zum Login
+                </a>
+            </div>
+        </div>
+    </div>
+{% endblock %}
diff --git a/templates/account/personal_data.html.twig b/templates/account/personal_data.html.twig
index 3dad7b24..7dab7054 100644
--- a/templates/account/personal_data.html.twig
+++ b/templates/account/personal_data.html.twig
@@ -15,6 +15,14 @@
             } %}
         </div>
     {% endif %}
+    {% if forcePasswordChange %}
+        <div class="mx-4 lg:mx-8">
+            {% include '_partials/_alert.html.twig' with {
+                level: 'info',
+                messages: ['Bitte lege zuerst ein neues Passwort fest, um dein Konto zu aktivieren.']
+            } %}
+        </div>
+    {% endif %}
     <div class="p-4 lg:p-8">
         <div class="divide-y divide-primary-bg/40">
             <div class="grid md:grid-cols-2 gap-x-8 gap-y-4 pb-8">
@@ -72,7 +80,9 @@
                         <h3 class="text-white">
                             Passwort ändern
                         </h3>
-                        {{ form_row(personalDataForm.currentPassword, { 'label_attr': { 'class': 'text-white' } }) }}
+                        {% if not forcePasswordChange %}
+                            {{ form_row(personalDataForm.currentPassword, { 'label_attr': { 'class': 'text-white' } }) }}
+                        {% endif %}
                         {{ form_row(personalDataForm.newPassword.first, { 'label_attr': { 'class': 'text-white' } }) }}
                         {{ form_row(personalDataForm.newPassword.second, { 'label_attr': { 'class': 'text-white' } }) }}
                     </div>
diff --git a/templates/booking/create/step_4.html.twig b/templates/booking/create/step_4.html.twig
index 594b6423..a18bbd82 100644
--- a/templates/booking/create/step_4.html.twig
+++ b/templates/booking/create/step_4.html.twig
@@ -486,6 +486,11 @@
                                     'label_attr': {'class': 'text-base font-semibold'}
                                 }) }}
                             {% endif %}
+                            {% if form.guestAccountOptIn is defined %}
+                                {{ form_row(form.guestAccountOptIn, {
+                                    'label_attr': {'class': 'text-base font-semibold'}
+                                }) }}
+                            {% endif %}
                             {{ form_row(form.confirmationAccepted, {
                                 'label_attr': {'class': 'text-base font-semibold'}
                             }) }}
diff --git a/templates/email/booking_guest_account_welcome.html.twig b/templates/email/booking_guest_account_welcome.html.twig
new file mode 100644
index 00000000..a8addce5
--- /dev/null
+++ b/templates/email/booking_guest_account_welcome.html.twig
@@ -0,0 +1,21 @@
+{% extends 'email/layout.html.twig' %}
+
+{% block body %}
+    <h1>
+        Dein MyE&amp;P Konto
+    </h1>
+    <p>
+        Für deine Buchung wurde ein MyE&amp;P-Konto angelegt.
+    </p>
+    <p>
+        Über den folgenden Link meldest du dich einmalig an und legst direkt ein neues Passwort fest.
+    </p>
+    <p>
+        <a href="{{ activationUrl }}" class="button">
+            Passwort jetzt festlegen
+        </a>
+    </p>
+    <p>
+        Wenn du diese Buchung nicht erstellt hast, kannst du diese E-Mail ignorieren.
+    </p>
+{% endblock %}
diff --git a/templates/security/login.html.twig b/templates/security/login.html.twig
index cafb8446..8bfd8721 100644
--- a/templates/security/login.html.twig
+++ b/templates/security/login.html.twig
@@ -53,6 +53,48 @@
                     Jetzt registrieren
                 </a>
             </div>
+
+            <div class="mt-10 pt-8 border-t border-primary-bg/40">
+                <h2 class="text-white uppercase mb-4">
+                    Portalzugang anfordern
+                </h2>
+                <p class="text-white mb-4">
+                    Du hast noch keinen Portalzugang? Gib die E-Mail-Adresse aus deiner Buchung und deine Buchungsnummer ein.
+                    Wenn deine Angaben zur Buchung passen, senden wir dir einen Aktivierungslink an diese E-Mail-Adresse.
+                </p>
+
+                <form action="{{ path('app_portal_access_request') }}" method="post">
+                    <div class="mb-4">
+                        <label for="portal_access_email" class="mb-1 font-semibold text-white">
+                            E-Mail:
+                        </label>
+                        <input type="email"
+                               id="portal_access_email"
+                               name="email"
+                               class="form-field"
+                               required
+                               autocomplete="email">
+                    </div>
+
+                    <div class="mb-4">
+                        <label for="portal_access_booking_number" class="mb-1 font-semibold text-white">
+                            Buchungsnummer:
+                        </label>
+                        <input type="number"
+                               id="portal_access_booking_number"
+                               name="bookingNumber"
+                               class="form-field"
+                               required
+                               min="1"
+                               inputmode="numeric">
+                    </div>
+
+                    <button type="submit" class="button button--primary">
+                        Portalzugang anfordern
+                    </button>
+                    <input type="hidden" name="_token" value="{{ csrf_token('portal_access_request') }}">
+                </form>
+            </div>
         </div>
         <div>
             <h3 class="mb-2 text-white">
diff --git a/tests/BpnConnect/BpnConnectClientTest.php b/tests/BpnConnect/BpnConnectClientTest.php
new file mode 100644
index 00000000..35506c8b
--- /dev/null
+++ b/tests/BpnConnect/BpnConnectClientTest.php
@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\BpnConnect;
+
+use App\BpnConnect\BpnConnectClient;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\HttpClient\MockHttpClient;
+use Symfony\Component\HttpClient\Response\MockResponse;
+
+class BpnConnectClientTest extends TestCase
+{
+    public function testLookupBookingMapsResponse(): void
+    {
+        $capturedMethod = null;
+        $capturedUrl = null;
+        $capturedOptions = null;
+        $httpClient = new MockHttpClient(static function (string $method, string $url, array $options) use (&$capturedMethod, &$capturedUrl, &$capturedOptions): MockResponse {
+            $capturedMethod = $method;
+            $capturedUrl = $url;
+            $capturedOptions = $options;
+
+            return new MockResponse(json_encode([
+                'bookingNumber' => 111386,
+                'bookingId' => 98609,
+                'addressId' => 225672,
+                'personId' => 412344,
+                'email' => 'bar-teilnehmer.in1@example.com',
+                'firstName' => 'Vorname 1',
+                'lastName' => 'Mustermann 1',
+            ], JSON_THROW_ON_ERROR), [
+                'response_headers' => ['content-type' => 'application/json'],
+            ]);
+        }, 'https://bpn-connect.test/');
+
+        $booking = (new BpnConnectClient($httpClient, new NullLogger()))->lookupBooking(' BAR-Teilnehmer.IN1@example.com ', 111386);
+
+        self::assertSame('GET', $capturedMethod);
+        self::assertSame('https://bpn-connect.test/api/bookings/lookup?email=bar-teilnehmer.in1@example.com&bookingNumber=111386', $capturedUrl);
+        self::assertSame(111386, $capturedOptions['query']['bookingNumber']);
+        self::assertSame(98609, $booking?->bookingId);
+        self::assertSame(225672, $booking?->addressId);
+        self::assertSame(412344, $booking?->personId);
+        self::assertSame('bar-teilnehmer.in1@example.com', $booking?->email);
+        self::assertSame('Vorname 1', $booking?->firstName);
+        self::assertSame('Mustermann 1', $booking?->lastName);
+    }
+
+    public function testLookupBookingReturnsNullForNotFound(): void
+    {
+        $httpClient = new MockHttpClient(new MockResponse('', ['http_code' => 404]), 'https://bpn-connect.test/');
+
+        self::assertNull((new BpnConnectClient($httpClient, new NullLogger()))->lookupBooking('customer@example.com', 123));
+    }
+}
diff --git a/tests/BusProNet/XmlParser/BookingResponseParserTest.php b/tests/BusProNet/XmlParser/BookingResponseParserTest.php
index 90b186fe..504f34d1 100644
--- a/tests/BusProNet/XmlParser/BookingResponseParserTest.php
+++ b/tests/BusProNet/XmlParser/BookingResponseParserTest.php
@@ -17,6 +17,22 @@ class BookingResponseParserTest extends TestCase
         $this->parser = new BookingResponseParser();
     }
 
+    public function testParseSuccessfulBookingResponse(): void
+    {
+        $xmlContent = '<?xml version="1.0" encoding="utf-8"?>
+<ergebnis>
+    <satz typ="BUCHUNG" />
+    <buchung>erfolgt</buchung>
+    <vorgang>321530</vorgang>
+</ergebnis>';
+
+        $crawler = new Crawler($xmlContent);
+        $response = $this->parser->parse($crawler->filter('ergebnis'));
+
+        self::assertTrue($response->isBookingSuccessful());
+        self::assertSame(321530, $response->bookingNumber);
+    }
+
     public function testParseBookingResponseWithPurchaseVoucher(): void
     {
         $xmlContent = '<?xml version="1.0" encoding="utf-8"?>
diff --git a/tests/Command/CleanupGuestInviteAccountsCommandTest.php b/tests/Command/CleanupGuestInviteAccountsCommandTest.php
new file mode 100644
index 00000000..07f2ae99
--- /dev/null
+++ b/tests/Command/CleanupGuestInviteAccountsCommandTest.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Command;
+
+use App\Command\CleanupGuestInviteAccountsCommand;
+use App\Repository\UserRepository;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Console\Tester\CommandTester;
+
+class CleanupGuestInviteAccountsCommandTest extends TestCase
+{
+    public function testCommandReportsWhenNothingWasDeleted(): void
+    {
+        $repository = $this->createMock(UserRepository::class);
+        $repository
+            ->expects(self::once())
+            ->method('deleteExpiredDormantGuestInvites')
+            ->with(self::isInstanceOf(\DateTimeImmutable::class))
+            ->willReturn(0);
+
+        $logger = $this->createMock(LoggerInterface::class);
+        $logger->expects(self::never())->method('info');
+
+        $tester = new CommandTester(new CleanupGuestInviteAccountsCommand($repository, $logger));
+        $exitCode = $tester->execute([]);
+
+        self::assertSame(0, $exitCode);
+        self::assertStringContainsString('No expired dormant guest accounts found.', $tester->getDisplay());
+    }
+
+    public function testCommandLogsAndReportsDeletionCount(): void
+    {
+        $repository = $this->createMock(UserRepository::class);
+        $repository
+            ->expects(self::once())
+            ->method('deleteExpiredDormantGuestInvites')
+            ->with(self::isInstanceOf(\DateTimeImmutable::class))
+            ->willReturn(3);
+
+        $logger = $this->createMock(LoggerInterface::class);
+        $logger
+            ->expects(self::once())
+            ->method('info')
+            ->with(
+                'Deleted expired dormant guest accounts',
+                self::callback(static fn (array $context): bool => 3 === $context['count'])
+            );
+
+        $tester = new CommandTester(new CleanupGuestInviteAccountsCommand($repository, $logger));
+        $exitCode = $tester->execute([]);
+
+        self::assertSame(0, $exitCode);
+        self::assertStringContainsString('Deleted 3 expired dormant guest account(s).', $tester->getDisplay());
+    }
+}
diff --git a/tests/Controller/Account/GuestAccountActivationControllerTest.php b/tests/Controller/Account/GuestAccountActivationControllerTest.php
new file mode 100644
index 00000000..478fa21d
--- /dev/null
+++ b/tests/Controller/Account/GuestAccountActivationControllerTest.php
@@ -0,0 +1,113 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Account;
+
+use App\Entity\User;
+use App\Exception\GuestAccountActivationExpiredException;
+use App\Service\BookingGuestAccountManager;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+class GuestAccountActivationControllerTest extends WebTestCase
+{
+    public function testExpiredActivationLinkShowsResendPageInsteadOf404(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('validateActivationRequest')
+            ->with(self::isInstanceOf(Request::class))
+            ->willThrowException(new GuestAccountActivationExpiredException());
+        $guestAccountManager->expects(self::never())->method('consumeActivation');
+        $guestAccountManager->expects(self::never())->method('validateActivationUrlForResend');
+        $guestAccountManager->expects(self::never())->method('resendWelcomeEmail');
+
+        $security = $this->createMock(Security::class);
+        $security->expects(self::never())->method('login');
+
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+        self::getContainer()->set(Security::class, $security);
+
+        $client->request('GET', '/welcome/activate?email=customer@example.com&nonce=current-nonce&expires=9999999999&_hash=signature');
+
+        self::assertResponseIsSuccessful();
+        self::assertStringContainsString('Link', $client->getResponse()->getContent());
+        self::assertStringContainsString('Willkommens-E-Mail erneut senden', $client->getResponse()->getContent());
+    }
+
+    public function testResendActionResendsWelcomeMailAndRedirectsToLogin(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $user = new User('customer@example.com');
+        $user->setWelcomeActivationNonce('current-nonce');
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('validateActivationRequest')
+            ->with(self::isInstanceOf(Request::class))
+            ->willThrowException(new GuestAccountActivationExpiredException());
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('validateActivationUrlForResend')
+            ->with(self::callback(static function (string $activationUrl): bool {
+                return str_contains($activationUrl, 'email=customer%40example.com')
+                    || str_contains($activationUrl, 'email=customer@example.com');
+            }))
+            ->willReturn($user);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('resendWelcomeEmail')
+            ->with($user);
+
+        $security = $this->createMock(Security::class);
+        $security->expects(self::never())->method('login');
+
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+        self::getContainer()->set(Security::class, $security);
+
+        $crawler = $client->request('GET', '/welcome/activate?email=customer@example.com&nonce=current-nonce&expires=9999999999&_hash=signature');
+        self::assertResponseIsSuccessful();
+
+        $form = $crawler->selectButton('Willkommens-E-Mail erneut senden')->form();
+        $client->submit($form);
+
+        self::assertResponseRedirects('/');
+        $client->followRedirect();
+
+        self::assertStringContainsString('Wir haben dir die Willkommens-E-Mail erneut gesendet.', $client->getResponse()->getContent());
+    }
+
+    public function testTamperedActivationLinkStillReturns404(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('validateActivationRequest')
+            ->with(self::isInstanceOf(Request::class))
+            ->willThrowException(new NotFoundHttpException());
+        $guestAccountManager->expects(self::never())->method('consumeActivation');
+
+        $security = $this->createMock(Security::class);
+        $security->expects(self::never())->method('login');
+
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+        self::getContainer()->set(Security::class, $security);
+
+        $client->request('GET', '/welcome/activate?email=customer@example.com&nonce=current-nonce&expires=9999999999&_hash=invalid');
+
+        self::assertResponseStatusCodeSame(404);
+    }
+}
diff --git a/tests/Controller/Account/PersonalDataControllerTest.php b/tests/Controller/Account/PersonalDataControllerTest.php
index eb921ccc..0e11c993 100644
--- a/tests/Controller/Account/PersonalDataControllerTest.php
+++ b/tests/Controller/Account/PersonalDataControllerTest.php
@@ -256,6 +256,59 @@ class PersonalDataControllerTest extends TestCase
         ], $controller->flashes);
     }
 
+    public function testIndexConsumesWelcomeActivationAfterForcedPasswordChangeSucceeds(): void
+    {
+        $personalData = $this->createCompletePersonalData();
+        $controller = $this->createController(true, true, $this->validator(), 'NewPassw0rd!');
+        $controller->user->markWelcomeActivationPending('current-nonce', new \DateTimeImmutable('+30 minutes'));
+
+        $controller->apiClient
+            ->expects(self::once())
+            ->method('getPersonalData')
+            ->with('customer@example.com', null, null)
+            ->willReturn($personalData);
+        $controller->apiClient
+            ->expects(self::once())
+            ->method('updatePersonalData')
+            ->with('customer@example.com', $personalData)
+            ->willReturn($personalData);
+        $controller->newsletterManager
+            ->expects(self::once())
+            ->method('hasConfirmedOptIn')
+            ->with('customer@example.com')
+            ->willReturn(false);
+        $controller->newsletterManager
+            ->expects(self::once())
+            ->method('hasPendingConfirmation')
+            ->with('customer@example.com')
+            ->willReturn(false);
+        $controller->dataLoader
+            ->expects(self::once())
+            ->method('invalidateUserBookingCaches')
+            ->with($controller->user);
+        $controller->entityManager
+            ->expects(self::once())
+            ->method('flush');
+        $controller->passwordHasher
+            ->expects(self::once())
+            ->method('hashPassword')
+            ->with($controller->user, 'NewPassw0rd!')
+            ->willReturn('new-local-hash');
+
+        $request = Request::create('/personal-data', 'POST');
+        $request->setSession(new Session(new MockArraySessionStorage()));
+        $request->getSession()->set(PersonalDataController::SESSION_FORCE_PASSWORD_CHANGE_KEY, true);
+
+        $response = $controller->index($request);
+
+        self::assertSame(302, $response->getStatusCode());
+        self::assertSame('new-local-hash', $controller->user->getPassword());
+        self::assertNull($controller->user->getWelcomeActivationNonce());
+        self::assertNull($controller->user->getWelcomeActivationExpiresAt());
+        self::assertNotNull($controller->user->getWelcomeActivatedAt());
+        self::assertFalse($request->getSession()->has(PersonalDataController::SESSION_FORCE_PASSWORD_CHANGE_KEY));
+    }
+
     public function testIndexDoesNotPersistInvalidFormSubmission(): void
     {
         $controller = $this->createController(true, false, $this->validator(), 'NewPassw0rd!');
diff --git a/tests/Controller/Account/PortalAccessRequestControllerTest.php b/tests/Controller/Account/PortalAccessRequestControllerTest.php
new file mode 100644
index 00000000..e3d4c0cc
--- /dev/null
+++ b/tests/Controller/Account/PortalAccessRequestControllerTest.php
@@ -0,0 +1,151 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Account;
+
+use App\Service\BookingGuestAccountManager;
+use App\Service\PublicFormRateLimiter;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+use Symfony\Component\HttpFoundation\Request;
+
+class PortalAccessRequestControllerTest extends WebTestCase
+{
+    public function testPortalAccessRequestRedirectsToLoginAfterSendingActivationMail(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $rateLimiter = $this->createMock(PublicFormRateLimiter::class);
+        $rateLimiter
+            ->expects(self::once())
+            ->method('isPortalAccessAllowed')
+            ->with('customer@example.com', self::isInstanceOf(Request::class))
+            ->willReturn(true);
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('requestPortalAccess')
+            ->with('customer@example.com', 123)
+            ->willReturn(BookingGuestAccountManager::PORTAL_ACCESS_SENT);
+
+        self::getContainer()->set(PublicFormRateLimiter::class, $rateLimiter);
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+
+        $crawler = $client->request('GET', '/');
+        $token = $crawler->filter('input[name="_token"]')->attr('value');
+        $client->request('POST', '/portal-access/request', [
+            'email' => 'customer@example.com',
+            'bookingNumber' => '123',
+            '_token' => $token,
+        ]);
+
+        self::assertResponseRedirects('/');
+        $client->followRedirect();
+
+        self::assertStringContainsString('Wenn zu deiner Buchung ein Portalzugang möglich ist, haben wir dir eine E-Mail gesendet.', $client->getResponse()->getContent());
+    }
+
+    public function testPortalAccessRequestRejectsMismatchedBookingGenerically(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $rateLimiter = $this->createMock(PublicFormRateLimiter::class);
+        $rateLimiter
+            ->expects(self::once())
+            ->method('isPortalAccessAllowed')
+            ->with('customer@example.com', self::isInstanceOf(Request::class))
+            ->willReturn(true);
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('requestPortalAccess')
+            ->with('customer@example.com', 123)
+            ->willReturn(BookingGuestAccountManager::PORTAL_ACCESS_NOT_SENT);
+
+        self::getContainer()->set(PublicFormRateLimiter::class, $rateLimiter);
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+
+        $crawler = $client->request('GET', '/');
+        $token = $crawler->filter('input[name="_token"]')->attr('value');
+        $client->request('POST', '/portal-access/request', [
+            'email' => 'customer@example.com',
+            'bookingNumber' => '123',
+            '_token' => $token,
+        ]);
+
+        self::assertResponseRedirects('/');
+        $client->followRedirect();
+
+        self::assertStringContainsString('Wenn zu deiner Buchung ein Portalzugang möglich ist, haben wir dir eine E-Mail gesendet.', $client->getResponse()->getContent());
+    }
+
+    public function testPortalAccessRequestShowsLoginHintForAlreadyActiveAccount(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $rateLimiter = $this->createMock(PublicFormRateLimiter::class);
+        $rateLimiter
+            ->expects(self::once())
+            ->method('isPortalAccessAllowed')
+            ->with('customer@example.com', self::isInstanceOf(Request::class))
+            ->willReturn(true);
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('requestPortalAccess')
+            ->with('customer@example.com', 123)
+            ->willReturn(BookingGuestAccountManager::PORTAL_ACCESS_ALREADY_ACTIVE);
+
+        self::getContainer()->set(PublicFormRateLimiter::class, $rateLimiter);
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+
+        $crawler = $client->request('GET', '/');
+        $token = $crawler->filter('input[name="_token"]')->attr('value');
+        $client->request('POST', '/portal-access/request', [
+            'email' => 'customer@example.com',
+            'bookingNumber' => '123',
+            '_token' => $token,
+        ]);
+
+        self::assertResponseRedirects('/');
+        $client->followRedirect();
+
+        self::assertStringContainsString('Für diese E-Mail-Adresse besteht bereits ein aktiver Portalzugang.', $client->getResponse()->getContent());
+    }
+
+    public function testPortalAccessRequestReturns429WhenThrottled(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $rateLimiter = $this->createMock(PublicFormRateLimiter::class);
+        $rateLimiter
+            ->expects(self::once())
+            ->method('isPortalAccessAllowed')
+            ->with('customer@example.com', self::isInstanceOf(Request::class))
+            ->willReturn(false);
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager->expects(self::never())->method('requestPortalAccess');
+
+        self::getContainer()->set(PublicFormRateLimiter::class, $rateLimiter);
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+
+        $crawler = $client->request('GET', '/');
+        $token = $crawler->filter('input[name="_token"]')->attr('value');
+        $client->request('POST', '/portal-access/request', [
+            'email' => 'customer@example.com',
+            'bookingNumber' => '123',
+            '_token' => $token,
+        ]);
+
+        self::assertResponseStatusCodeSame(429);
+        self::assertStringContainsString(PublicFormRateLimiter::THROTTLED_MESSAGE, $client->getResponse()->getContent());
+    }
+}
diff --git a/tests/Controller/Booking/Create/Step4ControllerTest.php b/tests/Controller/Booking/Create/Step4ControllerTest.php
new file mode 100644
index 00000000..f4f49359
--- /dev/null
+++ b/tests/Controller/Booking/Create/Step4ControllerTest.php
@@ -0,0 +1,293 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Booking\Create;
+
+use App\BusProNet\ApiClient;
+use App\BusProNet\Constants;
+use App\BusProNet\Model\BookingResponse;
+use App\BusProNet\Model\Hotel;
+use App\BusProNet\Model\Travel;
+use App\Entity\User;
+use App\Form\Model\BookingCreateContext;
+use App\Form\Model\BookingDto;
+use App\Form\Model\BookingSummaryDto;
+use App\Form\Model\BookingSummaryPricingDto;
+use App\Form\Model\BookingSummaryVoucherDto;
+use App\Form\Model\ParticipantDto;
+use App\Form\Model\RoomGroupsDto;
+use App\Repository\UserRepository;
+use App\Service\BookingConfigurator;
+use App\Service\BookingCreateContextFactory;
+use App\Service\BookingGuestAccountManager;
+use App\Service\BookingSessionManager;
+use App\Service\NewsletterManager;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+use Symfony\Bundle\SecurityBundle\Security;
+
+class Step4ControllerTest extends WebTestCase
+{
+    protected function tearDown(): void
+    {
+        self::ensureKernelShutdown();
+        parent::tearDown();
+    }
+
+    public function testStep4RendersCheckboxAndProvisionsGuestAccountAfterSuccessfulBooking(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $bookingDto = $this->createBookingDto();
+        $context = $this->createBookingContext($bookingDto);
+
+        $bookingSessionManager = $this->createMock(BookingSessionManager::class);
+        $bookingSessionManager
+            ->expects(self::exactly(2))
+            ->method('getOrCreateBookingCreateDto')
+            ->willReturn($bookingDto);
+
+        $contextFactory = $this->createMock(BookingCreateContextFactory::class);
+        $contextFactory
+            ->expects(self::exactly(2))
+            ->method('createWithParticipantPrices')
+            ->with($bookingDto)
+            ->willReturn($context);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::exactly(2))
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(null);
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('provisionGuestAccountForBooking')
+            ->with('customer@example.com', 123, 'Alice', 'Example')
+            ->willReturn(true);
+
+        $bookingConfigurator = $this->createMock(BookingConfigurator::class);
+        $bookingConfigurator
+            ->expects(self::once())
+            ->method('applyCreateBookingStatusRules');
+
+        $apiClient = $this->createMock(ApiClient::class);
+        $apiClient
+            ->expects(self::once())
+            ->method('createBooking')
+            ->with($bookingDto)
+            ->willReturn(new BookingResponse(BookingResponse::BOOKING_PROCESSED, 123));
+
+        $newsletterManager = $this->createMock(NewsletterManager::class);
+        $newsletterManager->expects(self::never())->method('requestConfirmation');
+
+        self::getContainer()->set(BookingSessionManager::class, $bookingSessionManager);
+        self::getContainer()->set(BookingCreateContextFactory::class, $contextFactory);
+        self::getContainer()->set(UserRepository::class, $userRepository);
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+        self::getContainer()->set(BookingConfigurator::class, $bookingConfigurator);
+        self::getContainer()->set(ApiClient::class, $apiClient);
+        self::getContainer()->set(NewsletterManager::class, $newsletterManager);
+
+        $crawler = $client->request('GET', '/bookings/create/confirmation');
+        self::assertResponseIsSuccessful();
+        self::assertStringContainsString('Benutzeraccount in MyE&P anlegen', $client->getResponse()->getContent());
+
+        $form = $crawler->selectButton('Verbindlich buchen')->form([
+            'booking_create_step4[confirmationAccepted]' => '1',
+            'booking_create_step4[termsAccepted]' => '1',
+            'booking_create_step4[guestAccountOptIn]' => '1',
+        ]);
+        $client->submit($form);
+
+        self::assertResponseRedirects('/bookings/create/success');
+    }
+
+    public function testStep4HidesGuestAccountCheckboxForAuthenticatedUsers(): void
+    {
+        $bookingDto = $this->createBookingDto();
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository->expects(self::never())->method('findOneByNormalizedEmail');
+
+        $controller = $this->createAuthenticatedController(
+            user: new User('logged@example.com'),
+            userRepository: $userRepository,
+        );
+
+        self::assertNull($controller->exposeGuestAccountTargetEmail($bookingDto));
+    }
+
+    public function testStep4HidesGuestAccountCheckboxWhenLocalUserAlreadyExists(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $bookingDto = $this->createBookingDto();
+        $context = $this->createBookingContext($bookingDto);
+
+        $bookingSessionManager = $this->createMock(BookingSessionManager::class);
+        $bookingSessionManager
+            ->expects(self::once())
+            ->method('getOrCreateBookingCreateDto')
+            ->willReturn($bookingDto);
+
+        $contextFactory = $this->createMock(BookingCreateContextFactory::class);
+        $contextFactory
+            ->expects(self::once())
+            ->method('createWithParticipantPrices')
+            ->with($bookingDto)
+            ->willReturn($context);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(new User('customer@example.com'));
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager->expects(self::never())->method('provisionGuestAccount');
+
+        self::getContainer()->set(BookingSessionManager::class, $bookingSessionManager);
+        self::getContainer()->set(BookingCreateContextFactory::class, $contextFactory);
+        self::getContainer()->set(UserRepository::class, $userRepository);
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+
+        $client->request('GET', '/bookings/create/confirmation');
+
+        self::assertResponseIsSuccessful();
+        self::assertStringNotContainsString('Benutzeraccount in MyE&P anlegen', $client->getResponse()->getContent());
+    }
+
+    public function testGuestAccountActivationRedirectsToPersonalDataAndForcesPasswordChange(): void
+    {
+        $client = self::createClient([], ['HTTPS' => 'on']);
+        $client->disableReboot();
+
+        $guestAccountManager = $this->createMock(BookingGuestAccountManager::class);
+        $guestAccountManager
+            ->expects(self::once())
+            ->method('validateActivationRequest')
+            ->with(self::isInstanceOf(\Symfony\Component\HttpFoundation\Request::class))
+            ->willReturn(new User('customer@example.com'));
+        $guestAccountManager
+            ->expects(self::never())
+            ->method('consumeActivation');
+
+        $security = $this->createMock(Security::class);
+        $security
+            ->expects(self::once())
+            ->method('login')
+            ->with(self::isInstanceOf(User::class), null, 'main')
+            ->willReturn(null);
+
+        self::getContainer()->set(BookingGuestAccountManager::class, $guestAccountManager);
+        self::getContainer()->set(Security::class, $security);
+
+        $client->request('GET', '/welcome/activate?email=customer@example.com&nonce=current-nonce&expires=9999999999&_hash=signature');
+
+        self::assertResponseRedirects('/personal-data');
+        self::assertTrue($client->getRequest()->getSession()->get(\App\Controller\Account\PersonalDataController::SESSION_FORCE_PASSWORD_CHANGE_KEY));
+    }
+
+    private function createBookingDto(): BookingDto
+    {
+        $travel = new Travel();
+        $travel->id = 123;
+        $travel->label = 'Winterreise';
+        $travel->productCode = 'PROD-1';
+        $travel->dateFrom = new \DateTimeImmutable('2026-01-01');
+        $travel->dateTo = new \DateTimeImmutable('2026-01-08');
+        $hotel = new Hotel();
+        $hotel->name = 'Hotel Test';
+        $travel->hotel = $hotel;
+
+        $bookingDto = new BookingDto($travel, 77);
+        $bookingDto->currentStep = 4;
+        $bookingDto->bookingStatus = 'F';
+        $bookingDto->paymentMethod = Constants::PAYMENT_METHOD_TRANSFER;
+
+        $participant = new ParticipantDto();
+        $participant->index = 0;
+        $participant->firstName = 'Alice';
+        $participant->lastName = 'Example';
+        $participant->email = 'Customer@Example.COM';
+        $participant->gender = 'M';
+        $participant->nationality = 'DE';
+        $participant->dateOfBirth = new \DateTimeImmutable('1990-01-01');
+        $bookingDto->participants = [$participant];
+
+        return $bookingDto;
+    }
+
+    private function createBookingContext(BookingDto $bookingDto): BookingCreateContext
+    {
+        $pricing = new BookingSummaryPricingDto([], [], null, [], 0.0);
+        $vouchers = new BookingSummaryVoucherDto(null, 0.0);
+        $summary = new BookingSummaryDto([], 1, $pricing, $vouchers, null);
+
+        return new BookingCreateContext(
+            bookingDto: $bookingDto,
+            summaryData: $summary,
+            groupedRooms: new RoomGroupsDto([], []),
+            participantPrices: [0.0],
+        );
+    }
+
+    private function createAuthenticatedController(User $user, UserRepository $userRepository): TestableStep4Controller
+    {
+        return new TestableStep4Controller(
+            $this->createMock(BookingConfigurator::class),
+            $this->createMock(BookingSessionManager::class),
+            $this->createMock(BookingCreateContextFactory::class),
+            $this->createMock(BookingGuestAccountManager::class),
+            $this->createMock(ApiClient::class),
+            $this->createMock(\Symfony\Contracts\Cache\CacheInterface::class),
+            $this->createMock(NewsletterManager::class),
+            $userRepository,
+            $this->createMock(\Psr\Log\LoggerInterface::class),
+            $user,
+        );
+    }
+}
+
+final class TestableStep4Controller extends \App\Controller\Booking\Create\Step4Controller
+{
+    public function __construct(
+        BookingConfigurator $bookingService,
+        BookingSessionManager $bookingSessionService,
+        BookingCreateContextFactory $createContextFactory,
+        BookingGuestAccountManager $guestAccountManager,
+        ApiClient $apiClient,
+        \Symfony\Contracts\Cache\CacheInterface $cache,
+        NewsletterManager $doubleOptInService,
+        UserRepository $userRepository,
+        \Psr\Log\LoggerInterface $logger,
+        private readonly User $user,
+    ) {
+        parent::__construct(
+            $bookingService,
+            $bookingSessionService,
+            $createContextFactory,
+            $guestAccountManager,
+            $apiClient,
+            $cache,
+            $doubleOptInService,
+            $userRepository,
+            $logger,
+        );
+    }
+
+    public function exposeGuestAccountTargetEmail(BookingDto $bookingDto): ?string
+    {
+        return $this->resolveGuestAccountTargetEmail($bookingDto);
+    }
+
+    protected function getUser(): \Symfony\Component\Security\Core\User\UserInterface|null
+    {
+        return $this->user;
+    }
+}
diff --git a/tests/EventListener/ForcePasswordChangeRedirectListenerTest.php b/tests/EventListener/ForcePasswordChangeRedirectListenerTest.php
new file mode 100644
index 00000000..defcbf8c
--- /dev/null
+++ b/tests/EventListener/ForcePasswordChangeRedirectListenerTest.php
@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\EventListener;
+
+use App\Controller\Account\PersonalDataController;
+use App\Entity\User;
+use App\EventListener\ForcePasswordChangeRedirectListener;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use App\Htmx\HxRedirectResponse;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Session\Session;
+use Symfony\Component\HttpFoundation\Session\Storage\MockArraySessionStorage;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
+
+class ForcePasswordChangeRedirectListenerTest extends TestCase
+{
+    private HttpKernelInterface $kernel;
+
+    protected function setUp(): void
+    {
+        $this->kernel = $this->createMock(HttpKernelInterface::class);
+    }
+
+    public function testRedirectsAwayFromNonPersonalDataRoutesWhenPasswordChangeIsForced(): void
+    {
+        $listener = $this->createListener();
+        $request = $this->createRequest('/account', 'app_account');
+        $event = new RequestEvent($this->kernel, $request, HttpKernelInterface::MAIN_REQUEST);
+
+        $listener->onKernelRequest($event);
+
+        self::assertInstanceOf(RedirectResponse::class, $event->getResponse());
+        self::assertSame('/personal-data', $event->getResponse()->headers->get('Location'));
+    }
+
+    public function testAllowsPersonalDataRouteWhilePasswordChangeIsForced(): void
+    {
+        $listener = $this->createListener();
+        $request = $this->createRequest('/personal-data', 'app_personal_data');
+        $event = new RequestEvent($this->kernel, $request, HttpKernelInterface::MAIN_REQUEST);
+
+        $listener->onKernelRequest($event);
+
+        self::assertNull($event->getResponse());
+    }
+
+    public function testNewsletterSubRouteIsNoLongerExempt(): void
+    {
+        $listener = $this->createListener();
+        $request = $this->createRequest('/personal-data/newsletter', 'app_personal_data_newsletter', ['HX-Request' => 'true']);
+        $event = new RequestEvent($this->kernel, $request, HttpKernelInterface::MAIN_REQUEST);
+
+        $listener->onKernelRequest($event);
+
+        self::assertInstanceOf(HxRedirectResponse::class, $event->getResponse());
+        self::assertSame('/personal-data', $event->getResponse()->headers->get('HX-Redirect'));
+    }
+
+    public function testLogoutRouteRemainsReachable(): void
+    {
+        $listener = $this->createListener();
+        $request = $this->createRequest('/logout', 'app_logout');
+        $event = new RequestEvent($this->kernel, $request, HttpKernelInterface::MAIN_REQUEST);
+
+        $listener->onKernelRequest($event);
+
+        self::assertNull($event->getResponse());
+    }
+
+    /**
+     * @param array<string, string> $headers
+     */
+    private function createRequest(string $uri, string $route, array $headers = []): Request
+    {
+        $server = [];
+        foreach ($headers as $header => $value) {
+            $server['HTTP_'.strtoupper(str_replace('-', '_', $header))] = $value;
+        }
+
+        $request = Request::create($uri, 'GET', [], [], [], $server);
+        $request->setSession(new Session(new MockArraySessionStorage()));
+        $request->getSession()->set(PersonalDataController::SESSION_FORCE_PASSWORD_CHANGE_KEY, true);
+        $request->attributes->set('_route', $route);
+
+        return $request;
+    }
+
+    private function createListener(): ForcePasswordChangeRedirectListener
+    {
+        $security = $this->createMock(Security::class);
+        $security
+            ->method('getUser')
+            ->willReturn(new User('customer@example.com'));
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator
+            ->method('generate')
+            ->with('app_personal_data')
+            ->willReturn('/personal-data');
+
+        return new ForcePasswordChangeRedirectListener($security, $urlGenerator);
+    }
+}
diff --git a/tests/Repository/UserRepositoryTest.php b/tests/Repository/UserRepositoryTest.php
new file mode 100644
index 00000000..36329ae5
--- /dev/null
+++ b/tests/Repository/UserRepositoryTest.php
@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Repository;
+
+use App\Repository\UserRepository;
+use Doctrine\ORM\Query;
+use Doctrine\ORM\QueryBuilder;
+use PHPUnit\Framework\TestCase;
+
+class UserRepositoryTest extends TestCase
+{
+    public function testDeleteExpiredDormantGuestInvitesBuildsExpectedQuery(): void
+    {
+        $query = $this->createMock(Query::class);
+        $query
+            ->expects(self::once())
+            ->method('execute')
+            ->willReturn(2);
+
+        $threshold = new \DateTimeImmutable('2026-05-29 01:00:00');
+        $queryBuilder = $this->createMock(QueryBuilder::class);
+        $andWhereCalls = 0;
+        $queryBuilder
+            ->expects(self::once())
+            ->method('delete')
+            ->willReturnSelf();
+        $queryBuilder
+            ->expects(self::once())
+            ->method('where')
+            ->with('u.welcomeActivatedAt IS NULL')
+            ->willReturnSelf();
+        $queryBuilder
+            ->expects(self::exactly(2))
+            ->method('andWhere')
+            ->willReturnCallback(function (string $condition) use (&$andWhereCalls, $queryBuilder): QueryBuilder {
+                $expectedConditions = [
+                    'u.welcomeActivationExpiresAt IS NOT NULL',
+                    'u.welcomeActivationExpiresAt <= :threshold',
+                ];
+
+                self::assertSame($expectedConditions[$andWhereCalls], $condition);
+                ++$andWhereCalls;
+
+                return $queryBuilder;
+            });
+        $queryBuilder
+            ->expects(self::once())
+            ->method('setParameter')
+            ->with('threshold', $threshold)
+            ->willReturnSelf();
+        $queryBuilder
+            ->expects(self::once())
+            ->method('getQuery')
+            ->willReturn($query);
+
+        $repository = new class($queryBuilder) extends UserRepository {
+            public function __construct(private readonly QueryBuilder $queryBuilder)
+            {
+            }
+
+            public function createQueryBuilder($alias, $indexBy = null): QueryBuilder
+            {
+                return $this->queryBuilder;
+            }
+        };
+
+        self::assertSame(2, $repository->deleteExpiredDormantGuestInvites($threshold));
+    }
+}
diff --git a/tests/Service/BookingGuestAccountManagerTest.php b/tests/Service/BookingGuestAccountManagerTest.php
new file mode 100644
index 00000000..364278db
--- /dev/null
+++ b/tests/Service/BookingGuestAccountManagerTest.php
@@ -0,0 +1,623 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Service;
+
+use App\BpnConnect\BpnConnectClient;
+use App\BpnConnect\Model\BookingLookupResult;
+use App\Email\Mailer;
+use App\Entity\User;
+use App\Exception\GuestAccountActivationExpiredException;
+use App\Repository\UserRepository;
+use App\Service\BookingGuestAccountManager;
+use App\Service\UserBootstrapper;
+use Doctrine\ORM\EntityManagerInterface;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\NullLogger;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\UriSigner;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Mailer\Exception\TransportException;
+use Symfony\Component\PasswordHasher\Hasher\UserPasswordHasherInterface;
+use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
+
+class BookingGuestAccountManagerTest extends TestCase
+{
+    public function testProvisionGuestAccountCreatesCustomerAndSendsActivationMail(): void
+    {
+        $persistedUser = null;
+        $plainPassword = null;
+        $generatedRoute = null;
+        $generatedParameters = null;
+        $generatedReferenceType = null;
+        $capturedContext = null;
+        $capturedOptions = null;
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(null);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager
+            ->expects(self::once())
+            ->method('persist')
+            ->with(self::callback(static function (User $user) use (&$persistedUser): bool {
+                $persistedUser = $user;
+
+                return true;
+            }));
+        $entityManager
+            ->expects(self::once())
+            ->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher
+            ->expects(self::once())
+            ->method('hashPassword')
+            ->with(self::isInstanceOf(User::class), self::callback(static function (string $password) use (&$plainPassword): bool {
+                $plainPassword = $password;
+
+                return '' !== $password;
+            }))
+            ->willReturn('hashed-password');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator
+            ->expects(self::once())
+            ->method('generate')
+            ->willReturnCallback(static function (string $route, array $parameters, int $referenceType) use (&$generatedRoute, &$generatedParameters, &$generatedReferenceType): string {
+                $generatedRoute = $route;
+                $generatedParameters = $parameters;
+                $generatedReferenceType = $referenceType;
+
+                return 'https://example.test/welcome/activate?'.http_build_query($parameters);
+            });
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer
+            ->expects(self::once())
+            ->method('createAndSendEmail')
+            ->willReturnCallback(static function (array $context, array $options) use (&$capturedContext, &$capturedOptions): void {
+                $capturedContext = $context;
+                $capturedOptions = $options;
+            });
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer);
+        $uriSigner = new UriSigner('test-secret');
+
+        self::assertTrue($manager->provisionGuestAccount(' Customer@Example.COM ', 'Alice', 'Example', 12345, 67890));
+        self::assertSame('app_guest_account_activate', $generatedRoute);
+        self::assertSame(UrlGeneratorInterface::ABSOLUTE_URL, $generatedReferenceType);
+        self::assertSame('customer@example.com', $generatedParameters['email']);
+        self::assertSame($persistedUser?->getWelcomeActivationNonce(), $generatedParameters['nonce']);
+        self::assertTrue($uriSigner->check((string) $capturedContext['activationUrl']));
+        self::assertSame('customer@example.com', $capturedOptions['to']);
+        self::assertSame('Dein MyE&P Konto ist bereit', $capturedOptions['subject']);
+        self::assertSame('email/booking_guest_account_welcome.html.twig', $capturedOptions['template']);
+        self::assertSame('Alice', $capturedContext['firstName']);
+        self::assertSame('Example', $capturedContext['lastName']);
+        self::assertMatchesRegularExpression('/^[a-f0-9]{48}$/', (string) $plainPassword);
+        self::assertInstanceOf(User::class, $persistedUser);
+        self::assertSame('customer@example.com', $persistedUser->getEmail());
+        self::assertSame(12345, $persistedUser->getAddressId());
+        self::assertSame(67890, $persistedUser->getPersonId());
+        self::assertSame(['ROLE_USER', 'ROLE_CUSTOMER'], $persistedUser->getRoles());
+        self::assertSame([], $persistedUser->getHotelCodes());
+        self::assertTrue($persistedUser->isProfileComplete());
+        self::assertMatchesRegularExpression('/^[a-f0-9]{64}$/', (string) $persistedUser->getWelcomeActivationNonce());
+        self::assertInstanceOf(\DateTimeImmutable::class, $persistedUser->getWelcomeActivationExpiresAt());
+        self::assertNull($persistedUser->getWelcomeActivatedAt());
+    }
+
+    public function testProvisionGuestAccountReturnsFalseWhenLocalUserAlreadyExists(): void
+    {
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(new User('customer@example.com'));
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::never())->method('persist');
+        $entityManager->expects(self::never())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher->expects(self::never())->method('hashPassword');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator->expects(self::never())->method('generate');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer->expects(self::never())->method('createAndSendEmail');
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer);
+
+        self::assertFalse($manager->provisionGuestAccount('customer@example.com', 'Alice', 'Example'));
+    }
+
+    public function testRequestPortalAccessProvisionsGuestAccountWhenBookingMatches(): void
+    {
+        $persistedUser = null;
+        $capturedContext = null;
+        $capturedOptions = null;
+        $booking = $this->createLookupResult('customer@example.com', 123, 'Alice', 'Example');
+
+        $bpnConnectClient = $this->createMock(BpnConnectClient::class);
+        $bpnConnectClient
+            ->expects(self::once())
+            ->method('lookupBooking')
+            ->with('customer@example.com', 123)
+            ->willReturn($booking);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::exactly(2))
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturnOnConsecutiveCalls(null, null);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager
+            ->expects(self::once())
+            ->method('persist')
+            ->with(self::callback(static function (User $user) use (&$persistedUser): bool {
+                $persistedUser = $user;
+
+                return true;
+            }));
+        $entityManager->expects(self::once())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher
+            ->expects(self::once())
+            ->method('hashPassword')
+            ->willReturn('hashed-password');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator
+            ->expects(self::once())
+            ->method('generate')
+            ->willReturn('https://example.test/welcome/activate?email=customer@example.com&nonce=current&expires=9999999999');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer
+            ->expects(self::once())
+            ->method('createAndSendEmail')
+            ->willReturnCallback(static function (array $context, array $options) use (&$capturedContext, &$capturedOptions): void {
+                $capturedContext = $context;
+                $capturedOptions = $options;
+            });
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer, $bpnConnectClient);
+
+        self::assertSame(BookingGuestAccountManager::PORTAL_ACCESS_SENT, $manager->requestPortalAccess('Customer@Example.COM', 123));
+        self::assertInstanceOf(User::class, $persistedUser);
+        self::assertSame('customer@example.com', $persistedUser->getEmail());
+        self::assertSame(12345, $persistedUser->getAddressId());
+        self::assertSame(67890, $persistedUser->getPersonId());
+        self::assertSame('customer@example.com', $capturedOptions['to']);
+        self::assertSame('Alice', $capturedContext['firstName']);
+        self::assertSame('Example', $capturedContext['lastName']);
+        self::assertMatchesRegularExpression('/^[a-f0-9]{64}$/', (string) $persistedUser->getWelcomeActivationNonce());
+        self::assertInstanceOf(\DateTimeImmutable::class, $persistedUser->getWelcomeActivationExpiresAt());
+        self::assertNull($persistedUser->getWelcomeActivatedAt());
+    }
+
+    public function testRequestPortalAccessResendsPendingInviteWhenBookingMatches(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setAddressId(12345);
+        $user->setPersonId(67890);
+        $user->setWelcomeActivationNonce('current-nonce');
+        $user->setWelcomeActivationExpiresAt(new \DateTimeImmutable('+30 minutes'));
+        $booking = $this->createLookupResult('customer@example.com', 123, 'Alice', 'Example');
+
+        $bpnConnectClient = $this->createMock(BpnConnectClient::class);
+        $bpnConnectClient
+            ->expects(self::once())
+            ->method('lookupBooking')
+            ->with('customer@example.com', 123)
+            ->willReturn($booking);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn($user);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::once())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher->expects(self::never())->method('hashPassword');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator
+            ->expects(self::once())
+            ->method('generate')
+            ->willReturn('https://example.test/welcome/activate?email=customer@example.com&nonce=new-nonce&expires=9999999999');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer
+            ->expects(self::once())
+            ->method('createAndSendEmail');
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer, $bpnConnectClient);
+
+        self::assertSame(BookingGuestAccountManager::PORTAL_ACCESS_SENT, $manager->requestPortalAccess('customer@example.com', 123));
+        self::assertNotSame('current-nonce', $user->getWelcomeActivationNonce());
+        self::assertNull($user->getWelcomeActivatedAt());
+        self::assertInstanceOf(\DateTimeImmutable::class, $user->getWelcomeActivationExpiresAt());
+    }
+
+    public function testRequestPortalAccessUsesExistingUserIdsAndDoesNotMailActivatedAccount(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setAddressId(12345);
+        $user->setPersonId(67890);
+        $user->markWelcomeActivated();
+        $booking = $this->createLookupResult('customer@example.com', 123, 'Alice', 'Example');
+
+        $bpnConnectClient = $this->createMock(BpnConnectClient::class);
+        $bpnConnectClient
+            ->expects(self::once())
+            ->method('lookupBooking')
+            ->with('customer@example.com', 123)
+            ->willReturn($booking);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn($user);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::never())->method('persist');
+        $entityManager->expects(self::never())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher->expects(self::never())->method('hashPassword');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator->expects(self::never())->method('generate');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer->expects(self::never())->method('createAndSendEmail');
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer, $bpnConnectClient);
+
+        self::assertSame(BookingGuestAccountManager::PORTAL_ACCESS_ALREADY_ACTIVE, $manager->requestPortalAccess('customer@example.com', 123));
+    }
+
+    public function testProvisionGuestAccountForBookingFetchesBookingIdentifiers(): void
+    {
+        $persistedUser = null;
+        $booking = $this->createLookupResult('customer@example.com', 123, 'Alice', 'Example');
+
+        $bpnConnectClient = $this->createMock(BpnConnectClient::class);
+        $bpnConnectClient
+            ->expects(self::once())
+            ->method('lookupBooking')
+            ->with('customer@example.com', 123)
+            ->willReturn($booking);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(null);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager
+            ->expects(self::once())
+            ->method('persist')
+            ->with(self::callback(static function (User $user) use (&$persistedUser): bool {
+                $persistedUser = $user;
+
+                return true;
+            }));
+        $entityManager->expects(self::once())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher
+            ->expects(self::once())
+            ->method('hashPassword')
+            ->willReturn('hashed-password');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator
+            ->expects(self::once())
+            ->method('generate')
+            ->willReturn('https://example.test/welcome/activate?email=customer@example.com&nonce=current&expires=9999999999');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer
+            ->expects(self::once())
+            ->method('createAndSendEmail');
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer, $bpnConnectClient);
+
+        self::assertTrue($manager->provisionGuestAccountForBooking('Customer@Example.COM', 123));
+        self::assertInstanceOf(User::class, $persistedUser);
+        self::assertSame('customer@example.com', $persistedUser->getEmail());
+        self::assertSame(12345, $persistedUser->getAddressId());
+        self::assertSame(67890, $persistedUser->getPersonId());
+    }
+
+    public function testRequestPortalAccessRejectsMismatchedBookingGenerically(): void
+    {
+        $booking = $this->createLookupResult('other@example.com', 123, 'Alice', 'Example');
+
+        $bpnConnectClient = $this->createMock(BpnConnectClient::class);
+        $bpnConnectClient
+            ->expects(self::once())
+            ->method('lookupBooking')
+            ->with('customer@example.com', 123)
+            ->willReturn($booking);
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(null);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::never())->method('persist');
+        $entityManager->expects(self::never())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher->expects(self::never())->method('hashPassword');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator->expects(self::never())->method('generate');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer->expects(self::never())->method('createAndSendEmail');
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer, $bpnConnectClient);
+
+        self::assertSame(BookingGuestAccountManager::PORTAL_ACCESS_NOT_SENT, $manager->requestPortalAccess('customer@example.com', 123));
+    }
+
+    public function testConsumeActivationMarksInviteAsActivated(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setWelcomeActivationNonce('current-nonce');
+        $user->setWelcomeActivationExpiresAt(new \DateTimeImmutable('+30 minutes'));
+
+        $manager = $this->createValidationManager($user);
+        $manager->consumeActivation($user);
+
+        self::assertNull($user->getWelcomeActivationNonce());
+        self::assertNull($user->getWelcomeActivationExpiresAt());
+        self::assertInstanceOf(\DateTimeImmutable::class, $user->getWelcomeActivatedAt());
+    }
+
+    public function testValidateActivationRequestAcceptsValidSignedRequestAndRejectsReplay(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setWelcomeActivationNonce('current-nonce');
+
+        $manager = $this->createValidationManager($user);
+        $request = Request::create(
+            $this->buildActivationUrl('customer@example.com', 'current-nonce', time() + 3600),
+            'GET'
+        );
+
+        self::assertSame($user, $manager->validateActivationRequest($request));
+
+        $manager->consumeActivation($user);
+
+        $this->expectException(NotFoundHttpException::class);
+        $manager->validateActivationRequest($request);
+    }
+
+    public function testValidateActivationRequestRejectsExpiredLink(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setWelcomeActivationNonce('current-nonce');
+
+        $manager = $this->createValidationManager($user);
+        $request = Request::create(
+            $this->buildActivationUrl('customer@example.com', 'current-nonce', time() - 60),
+            'GET'
+        );
+
+        $this->expectException(GuestAccountActivationExpiredException::class);
+        $manager->validateActivationRequest($request);
+    }
+
+    public function testValidateActivationUrlForResendAcceptsExpiredLink(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setWelcomeActivationNonce('current-nonce');
+
+        $manager = $this->createValidationManager($user);
+        $activationUrl = $this->buildActivationUrl('customer@example.com', 'current-nonce', time() - 60);
+
+        self::assertSame($user, $manager->validateActivationUrlForResend($activationUrl));
+    }
+
+    public function testResendWelcomeEmailRotatesNonceAndSendsActivationMail(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setWelcomeActivationNonce('old-nonce');
+
+        $generatedRoute = null;
+        $generatedParameters = null;
+        $generatedReferenceType = null;
+        $capturedContext = null;
+        $capturedOptions = null;
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $mailer = $this->createMock(Mailer::class);
+
+        $entityManager->expects(self::once())->method('flush');
+        $passwordHasher->expects(self::never())->method('hashPassword');
+        $userRepository->expects(self::never())->method('findOneByNormalizedEmail');
+        $urlGenerator
+            ->expects(self::once())
+            ->method('generate')
+            ->willReturnCallback(static function (string $route, array $parameters, int $referenceType) use (&$generatedRoute, &$generatedParameters, &$generatedReferenceType): string {
+                $generatedRoute = $route;
+                $generatedParameters = $parameters;
+                $generatedReferenceType = $referenceType;
+
+                return 'https://example.test/welcome/activate?'.http_build_query($parameters);
+            });
+        $mailer
+            ->expects(self::once())
+            ->method('createAndSendEmail')
+            ->willReturnCallback(static function (array $context, array $options) use (&$capturedContext, &$capturedOptions): void {
+                $capturedContext = $context;
+                $capturedOptions = $options;
+            });
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer);
+
+        $manager->resendWelcomeEmail($user);
+
+        self::assertSame('app_guest_account_activate', $generatedRoute);
+        self::assertSame(UrlGeneratorInterface::ABSOLUTE_URL, $generatedReferenceType);
+        self::assertSame('customer@example.com', $generatedParameters['email']);
+        self::assertSame($user->getWelcomeActivationNonce(), $generatedParameters['nonce']);
+        self::assertSame('customer@example.com', $capturedOptions['to']);
+        self::assertSame('Dein MyE&P Konto ist bereit', $capturedOptions['subject']);
+        self::assertSame('email/booking_guest_account_welcome.html.twig', $capturedOptions['template']);
+        self::assertTrue((new UriSigner('test-secret'))->check((string) $capturedContext['activationUrl']));
+        self::assertNotSame('old-nonce', $user->getWelcomeActivationNonce());
+        self::assertMatchesRegularExpression('/^[a-f0-9]{64}$/', (string) $user->getWelcomeActivationNonce());
+    }
+
+    public function testProvisionGuestAccountKeepsPersistedUserWhenMailSendFails(): void
+    {
+        $persistedUser = null;
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->expects(self::once())
+            ->method('findOneByNormalizedEmail')
+            ->with('customer@example.com')
+            ->willReturn(null);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager
+            ->expects(self::once())
+            ->method('persist')
+            ->with(self::callback(static function (User $user) use (&$persistedUser): bool {
+                $persistedUser = $user;
+
+                return true;
+            }));
+        $entityManager->expects(self::once())->method('flush');
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $passwordHasher
+            ->expects(self::once())
+            ->method('hashPassword')
+            ->willReturn('hashed-password');
+
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $urlGenerator
+            ->expects(self::once())
+            ->method('generate')
+            ->willReturn('https://example.test/welcome/activate?email=customer@example.com&nonce=current&expires=9999999999');
+
+        $mailer = $this->createMock(Mailer::class);
+        $mailer
+            ->expects(self::once())
+            ->method('createAndSendEmail')
+            ->willThrowException(new TransportException('smtp down'));
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer);
+
+        $this->expectException(TransportException::class);
+        try {
+            $manager->provisionGuestAccount('customer@example.com', 'Alice', 'Example');
+        } finally {
+            self::assertInstanceOf(User::class, $persistedUser);
+            self::assertSame('customer@example.com', $persistedUser->getEmail());
+            self::assertSame(['ROLE_USER', 'ROLE_CUSTOMER'], $persistedUser->getRoles());
+            self::assertTrue($persistedUser->isProfileComplete());
+            self::assertNotNull($persistedUser->getWelcomeActivationNonce());
+        }
+    }
+
+    private function createManager(
+        UserRepository $userRepository,
+        EntityManagerInterface $entityManager,
+        UserPasswordHasherInterface $passwordHasher,
+        UrlGeneratorInterface $urlGenerator,
+        Mailer $mailer,
+        ?BpnConnectClient $bpnConnectClient = null,
+    ): BookingGuestAccountManager {
+        $bpnConnectClient ??= $this->createMock(BpnConnectClient::class);
+
+        return new BookingGuestAccountManager(
+            $bpnConnectClient,
+            $userRepository,
+            $entityManager,
+            new UserBootstrapper(),
+            $passwordHasher,
+            $urlGenerator,
+            new UriSigner('test-secret'),
+            $mailer,
+            new NullLogger(),
+        );
+    }
+
+    private function createValidationManager(User $user): BookingGuestAccountManager
+    {
+        $userRepository = $this->createMock(UserRepository::class);
+        $userRepository
+            ->method('findOneByNormalizedEmail')
+            ->willReturnCallback(static function (string $email) use ($user): ?User {
+                return 'customer@example.com' === $email ? $user : null;
+            });
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $mailer = $this->createMock(Mailer::class);
+        $bpnConnectClient = $this->createMock(BpnConnectClient::class);
+
+        return $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer, $bpnConnectClient);
+    }
+
+    private function buildActivationUrl(string $email, string $nonce, int $expires): string
+    {
+        $baseUrl = 'https://example.test/welcome/activate?'.http_build_query([
+            'email' => $email,
+            'nonce' => $nonce,
+            'expires' => $expires,
+        ]);
+
+        return (new UriSigner('test-secret'))->sign($baseUrl);
+    }
+
+    private function createLookupResult(string $email, int $bookingNumber, string $firstName, string $lastName): BookingLookupResult
+    {
+        return new BookingLookupResult(
+            bookingNumber: $bookingNumber,
+            bookingId: 98765,
+            addressId: 12345,
+            personId: 67890,
+            email: $email,
+            firstName: $firstName,
+            lastName: $lastName,
+        );
+    }
+}
diff --git a/tests/Service/PasswordResetManagerTest.php b/tests/Service/PasswordResetManagerTest.php
index 60b3215c..a0b38abf 100644
--- a/tests/Service/PasswordResetManagerTest.php
+++ b/tests/Service/PasswordResetManagerTest.php
@@ -173,6 +173,35 @@ class PasswordResetManagerTest extends TestCase
         self::assertMatchesRegularExpression('/^[a-f0-9]{64}$/', (string) $user->getPasswordResetNonce());
     }
 
+    public function testResetPasswordClearsPendingWelcomeInvite(): void
+    {
+        $user = new User('customer@example.com');
+        $user->setPasswordResetNonce('current-nonce');
+        $user->markWelcomeActivationPending('welcome-nonce', new \DateTimeImmutable('-30 minutes'));
+
+        $userRepository = $this->createMock(UserRepository::class);
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $passwordHasher = $this->createMock(UserPasswordHasherInterface::class);
+        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
+        $mailer = $this->createMock(Mailer::class);
+
+        $passwordHasher
+            ->expects(self::once())
+            ->method('hashPassword')
+            ->with($user, 'new-password')
+            ->willReturn('hashed-password');
+        $entityManager->expects(self::once())->method('flush');
+
+        $manager = $this->createManager($userRepository, $entityManager, $passwordHasher, $urlGenerator, $mailer);
+
+        $manager->resetPassword($user, 'new-password');
+
+        self::assertSame('hashed-password', $user->getPassword());
+        self::assertNull($user->getWelcomeActivationNonce());
+        self::assertNull($user->getWelcomeActivationExpiresAt());
+        self::assertNotNull($user->getWelcomeActivatedAt());
+    }
+
     public function testNewPasswordResetRequestInvalidatesPreviousLink(): void
     {
         $user = new User('customer@example.com');
diff --git a/tests/Support/TestPublicFormRateLimiter.php b/tests/Support/TestPublicFormRateLimiter.php
index 5e4863bc..396c0a39 100644
--- a/tests/Support/TestPublicFormRateLimiter.php
+++ b/tests/Support/TestPublicFormRateLimiter.php
@@ -28,6 +28,11 @@ class TestPublicFormRateLimiter extends PublicFormRateLimiter
         return $this->consume($email, $request);
     }
 
+    public function isPortalAccessAllowed(string $email, Request $request): bool
+    {
+        return $this->consume($email, $request);
+    }
+
     public function createBucketKey(string $email, ?string $clientIp): string
     {
         return hash('sha256', mb_strtolower(trim($email)).'|'.($clientIp ?? 'unknown'));