diff --git a/src/BusProNet/Model/Booking.php b/src/BusProNet/Model/Booking.php
index 732042b..3a36806 100644
--- a/src/BusProNet/Model/Booking.php
+++ b/src/BusProNet/Model/Booking.php
@@ -15,6 +15,8 @@ use App\BusProNet\Constants;
  */
 class Booking
 {
+    public const string STATUS_CANCELED = 'S';
+
     public ?int $id = null;
     public ?int $agencyId = null;
     public ?int $bookingNumber = null;
diff --git a/src/BusProNet/Model/BookingResponse.php b/src/BusProNet/Model/BookingResponse.php
index b1f0da2..9d4cdaf 100644
--- a/src/BusProNet/Model/BookingResponse.php
+++ b/src/BusProNet/Model/BookingResponse.php
@@ -15,6 +15,10 @@ namespace App\BusProNet\Model;
  */
 class BookingResponse
 {
+    public const string BOOKING_POSSIBLE = 'möglich';
+    public const string BOOKING_IMPOSSIBLE = 'nicht möglich';
+    public const string BOOKING_PROCESSED = 'erfolgt';
+
     /**
      * @param string                $status        Booking status (möglich|erfolgt)
      * @param int|null              $bookingNumber Booking number (BPN XML: vorgang)
@@ -37,7 +41,7 @@ class BookingResponse
      */
     public function isInquiryValid(): bool
     {
-        return 'möglich' === $this->status;
+        return self::BOOKING_POSSIBLE === $this->status;
     }
 
     /**
@@ -45,7 +49,7 @@ class BookingResponse
      */
     public function isBookingSuccessful(): bool
     {
-        return 'erfolgt' === $this->status;
+        return self::BOOKING_PROCESSED === $this->status;
     }
 
     /**
diff --git a/src/Controller/Booking/Create/AbstractBookingCreateController.php b/src/Controller/Booking/Create/AbstractBookingCreateController.php
new file mode 100644
index 0000000..6af43b4
--- /dev/null
+++ b/src/Controller/Booking/Create/AbstractBookingCreateController.php
@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Booking\Create;
+
+use App\Exception\BookingSessionNotFoundException;
+use App\Exception\HotelNotInTravelException;
+use App\Exception\TravelNotFoundException;
+use App\Form\Model\BookingDto;
+use App\Service\BookingSessionManager;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+/**
+ * Shared base controller for booking creation steps.
+ */
+abstract class AbstractBookingCreateController extends AbstractController
+{
+    protected function loadBookingCreateDto(BookingSessionManager $bookingSessionService, Request $request): BookingDto
+    {
+        return $bookingSessionService->getOrCreateBookingCreateDto($request);
+    }
+
+    protected function createBookingCreateFailureResponse(\Throwable $exception, bool $htmx): Response
+    {
+        if (true === $htmx) {
+            return $this->createBookingCreateHtmxFailureResponse();
+        }
+
+        return $this->createBookingCreateRedirectFailureResponse($exception);
+    }
+
+    protected function validateStepAccess(BookingDto $bookingCreateDto, int $expectedStep): ?RedirectResponse
+    {
+        // Allow access to current step or any previous step
+        if ($expectedStep > $bookingCreateDto->currentStep) {
+            $this->addFlash('error', 'Bitte erst die vorherigen Schritte abschließen.');
+
+            return $this->redirectToCurrentStep($bookingCreateDto);
+        }
+
+        return null;
+    }
+
+    /**
+     * Handles API errors by logging and adding a flash message.
+     *
+     * @param array<string, mixed> $context
+     */
+    protected function handleApiError(
+        LoggerInterface $logger,
+        string $logMessage,
+        array $context,
+        string $flashMessage,
+    ): void {
+        $logger->error($logMessage, $context);
+        $this->addFlash('error', $flashMessage);
+    }
+
+    private function createBookingCreateRedirectFailureResponse(\Throwable $exception): Response
+    {
+        $message = match (true) {
+            $exception instanceof BookingSessionNotFoundException => 'Deine Buchungssitzung ist abgelaufen. Bitte starte eine neue Buchung.',
+            $exception instanceof TravelNotFoundException => 'Reisedaten sind nicht (mehr) verfügbar.',
+            $exception instanceof HotelNotInTravelException => 'Das gewählte Hotel ist für diese Reise nicht verfügbar.',
+            default => 'Die Buchung konnte nicht geladen werden.',
+        };
+
+        $this->addFlash('error', $message);
+
+        return $this->redirectToRoute('app_booking_create_error');
+    }
+
+    private function createBookingCreateHtmxFailureResponse(): Response
+    {
+        return new Response('', 400);
+    }
+
+    private function redirectToCurrentStep(BookingDto $bookingCreateDto): RedirectResponse
+    {
+        $route = match ($bookingCreateDto->currentStep) {
+            2 => 'app_booking_create_step_2',
+            3 => 'app_booking_create_step_3',
+            4 => 'app_booking_create_step_4',
+            default => 'app_booking_create_step_1',
+        };
+
+        return $this->redirectToRoute($route);
+    }
+}
diff --git a/src/Controller/Booking/Create/Step1Controller.php b/src/Controller/Booking/Create/Step1Controller.php
index d22d2f3..421a329 100644
--- a/src/Controller/Booking/Create/Step1Controller.php
+++ b/src/Controller/Booking/Create/Step1Controller.php
@@ -4,8 +4,9 @@ declare(strict_types=1);
 
 namespace App\Controller\Booking\Create;
 
-use App\Controller\Booking\Traits\BookingCreateTrait;
-use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
+use App\Exception\BookingSessionNotFoundException;
+use App\Exception\HotelNotInTravelException;
+use App\Exception\TravelNotFoundException;
 use App\Form\BookingCreateStep1Type;
 use App\Form\Model\BookingDto;
 use App\Htmx\HxTrait;
@@ -13,7 +14,6 @@ use App\Service\BookingConfigurator;
 use App\Service\BookingCreateContextFactory;
 use App\Service\BookingSessionManager;
 use App\Service\RoomPricingCalculator;
-use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Attribute\Route;
@@ -24,10 +24,8 @@ use Symfony\Component\Routing\Attribute\Route;
  * This controller manages room selection functionality where users
  * choose the types and quantities of rooms for their booking.
  */
-class Step1Controller extends AbstractController
+class Step1Controller extends AbstractBookingCreateController
 {
-    use BookingCreateTrait;
-    use BookingExceptionHandlerTrait;
     use HxTrait;
 
     public function __construct(
@@ -43,11 +41,11 @@ class Step1Controller extends AbstractController
     #[Route('/bookings/create/rooms', name: 'app_booking_create_step_1')]
     public function index(Request $request): Response
     {
-        $result = $this->getOrCreateBookingCreateDto($this->bookingSessionService, $request);
-        if ($result instanceof Response) {
-            return $result;
+        try {
+            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
+        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
+            return $this->createBookingCreateFailureResponse($exception, false);
         }
-        $bookingCreateDto = $result;
 
         // Get or create baseline snapshot for change detection
         $oldRoomSelectionSnapshot = $this->bookingSessionService->getOrCreateBaselineSnapshot($request, $bookingCreateDto);
@@ -98,11 +96,11 @@ class Step1Controller extends AbstractController
     #[Route('/bookings/create/refresh', name: 'app_booking_create_step_1_refresh', methods: ['POST'])]
     public function refresh(Request $request): Response
     {
-        $result = $this->getOrCreateBookingCreateDtoForHtmx($this->bookingSessionService, $request);
-        if ($result instanceof Response) {
-            return $result;
+        try {
+            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
+        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
+            return $this->createBookingCreateFailureResponse($exception, true);
         }
-        $bookingCreateDto = $result;
 
         // Process form data without validation to capture current state
         $form = $this->createForm(BookingCreateStep1Type::class, $bookingCreateDto, [
diff --git a/src/Controller/Booking/Create/Step2Controller.php b/src/Controller/Booking/Create/Step2Controller.php
index 5dc97ce..e4901de 100644
--- a/src/Controller/Booking/Create/Step2Controller.php
+++ b/src/Controller/Booking/Create/Step2Controller.php
@@ -5,19 +5,20 @@ declare(strict_types=1);
 namespace App\Controller\Booking\Create;
 
 use App\BusProNet\Model\Travel;
-use App\Controller\Booking\Traits\BookingCreateTrait;
-use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
+use App\Exception\BookingSessionNotFoundException;
+use App\Exception\HotelNotInTravelException;
+use App\Exception\TravelNotFoundException;
 use App\Entity\User;
 use App\Form\BookingCreateStep2Type;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
+use App\Form\Model\RoomSelectionDto;
 use App\Service\BookingConfigurator;
 use App\Service\BookingCreateContextFactory;
 use App\Service\BookingSessionManager;
 use App\Service\ParticipantDataPrefiller;
 use App\Service\RoomAssigner;
 use App\Service\TravelDataProvider;
-use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Attribute\Route;
@@ -28,11 +29,8 @@ use Symfony\Component\Routing\Attribute\Route;
  * This controller uses a card overview and lazy-loaded individual participant forms
  * for better performance and UX with large groups (50+ participants).
  */
-class Step2Controller extends AbstractController
+class Step2Controller extends AbstractBookingCreateController
 {
-    use BookingCreateTrait;
-    use BookingExceptionHandlerTrait;
-
     public function __construct(
         private readonly BookingConfigurator $bookingService,
         private readonly BookingSessionManager $bookingSessionService,
@@ -49,15 +47,14 @@ class Step2Controller extends AbstractController
     #[Route('/bookings/create/participants', name: 'app_booking_create_step_2')]
     public function index(Request $request): Response
     {
-        // Load or create booking DTO
-        $result = $this->getOrCreateBookingCreateDto($this->bookingSessionService, $request);
-        if ($result instanceof Response) {
-            return $result;
+        try {
+            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
+        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
+            return $this->createBookingCreateFailureResponse($exception, false);
         }
-        $bookingCreateDto = $result;
 
         // Validate step access
-        if ($redirect = $this->validateStepAccess($bookingCreateDto, 2)) {
+        if (null !== $redirect = $this->validateStepAccess($bookingCreateDto, 2)) {
             return $redirect;
         }
 
@@ -132,7 +129,9 @@ class Step2Controller extends AbstractController
         }
     }
 
-    /** @param array<int, \App\Form\Model\RoomSelectionDto> $roomSelections */
+    /**
+     * @param array<int, RoomSelectionDto> $roomSelections
+     */
     private function calculateParticipantsCount(array $roomSelections, Travel $travelData): int
     {
         $participantsCount = 0;
diff --git a/src/Controller/Booking/Create/Step3Controller.php b/src/Controller/Booking/Create/Step3Controller.php
index 55988d9..09f2881 100644
--- a/src/Controller/Booking/Create/Step3Controller.php
+++ b/src/Controller/Booking/Create/Step3Controller.php
@@ -8,8 +8,9 @@ use App\BusProNet\ApiClient;
 use App\BusProNet\Exception\TimeoutException;
 use App\BusProNet\Model\BookingResponse;
 use App\BusProNet\Model\Notification;
-use App\Controller\Booking\Traits\BookingCreateTrait;
-use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
+use App\Exception\BookingSessionNotFoundException;
+use App\Exception\HotelNotInTravelException;
+use App\Exception\TravelNotFoundException;
 use App\Form\BookingCreateStep3Type;
 use App\Form\Model\BookingDto;
 use App\Htmx\HxTrait;
@@ -20,7 +21,6 @@ use App\Service\BookingPriceMismatchAnalyzer;
 use App\Service\BookingSessionManager;
 use App\Service\RoomPricingCalculator;
 use Psr\Log\LoggerInterface;
-use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
@@ -29,10 +29,8 @@ use Symfony\Component\Routing\Attribute\Route;
 /**
  * Handles the third step of the booking creation process (payment method selection).
  */
-class Step3Controller extends AbstractController
+class Step3Controller extends AbstractBookingCreateController
 {
-    use BookingCreateTrait;
-    use BookingExceptionHandlerTrait;
     use HxTrait;
 
     public function __construct(
@@ -52,14 +50,14 @@ class Step3Controller extends AbstractController
     #[Route('/bookings/create/payment', name: 'app_booking_create_step_3')]
     public function index(Request $request): Response
     {
-        $result = $this->getOrCreateBookingCreateDto($this->bookingSessionService, $request);
-        if ($result instanceof Response) {
-            return $result;
+        try {
+            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
+        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
+            return $this->createBookingCreateFailureResponse($exception, false);
         }
-        $bookingCreateDto = $result;
 
         // Validate step access
-        if ($redirect = $this->validateStepAccess($bookingCreateDto, 3)) {
+        if (null !== $redirect = $this->validateStepAccess($bookingCreateDto, 3)) {
             return $redirect;
         }
 
@@ -203,11 +201,11 @@ class Step3Controller extends AbstractController
     #[Route('/bookings/create/payment/refresh', name: 'app_booking_create_step_3_refresh', methods: ['POST'])]
     public function refresh(Request $request): Response
     {
-        $result = $this->getOrCreateBookingCreateDto($this->bookingSessionService, $request);
-        if ($result instanceof Response) {
-            return $result;
+        try {
+            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
+        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
+            return $this->createBookingCreateFailureResponse($exception, true);
         }
-        $bookingCreateDto = $result;
 
         $form = $this->createForm(BookingCreateStep3Type::class, $bookingCreateDto, [
             'validation_groups' => false,
@@ -248,7 +246,7 @@ class Step3Controller extends AbstractController
     private function shouldFallbackToInquiryMode(BookingResponse $response): bool
     {
         // Check for "nicht möglich" status + inquiry suggestion in message
-        if ('nicht möglich' !== $response->status) {
+        if (BookingResponse::BOOKING_IMPOSSIBLE !== $response->status) {
             return false;
         }
 
diff --git a/src/Controller/Booking/Create/Step4Controller.php b/src/Controller/Booking/Create/Step4Controller.php
index ff5057f..07a9abd 100644
--- a/src/Controller/Booking/Create/Step4Controller.php
+++ b/src/Controller/Booking/Create/Step4Controller.php
@@ -7,10 +7,11 @@ namespace App\Controller\Booking\Create;
 use App\BusProNet\ApiClient;
 use App\BusProNet\Exception\TimeoutException;
 use App\BusProNet\Model\Notification;
-use App\Controller\Booking\Traits\BookingCreateTrait;
-use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
 use App\Entity\User;
+use App\Exception\BookingSessionNotFoundException;
+use App\Exception\HotelNotInTravelException;
 use App\Exception\NewsletterProviderException;
+use App\Exception\TravelNotFoundException;
 use App\Form\BookingCreateStep4Type;
 use App\Form\Model\BookingDto;
 use App\Htmx\HxTrait;
@@ -20,7 +21,6 @@ use App\Service\BookingSessionManager;
 use App\Service\MailjetApiClient;
 use App\Service\NewsletterManager;
 use Psr\Log\LoggerInterface;
-use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
@@ -30,10 +30,8 @@ use Symfony\Contracts\Cache\CacheInterface;
 /**
  * Handles the fourth step of the booking creation process (confirmation).
  */
-class Step4Controller extends AbstractController
+class Step4Controller extends AbstractBookingCreateController
 {
-    use BookingCreateTrait;
-    use BookingExceptionHandlerTrait;
     use HxTrait;
 
     public function __construct(
@@ -54,14 +52,14 @@ class Step4Controller extends AbstractController
     #[Route('/bookings/create/confirmation', name: 'app_booking_create_step_4')]
     public function index(Request $request): Response
     {
-        $result = $this->getOrCreateBookingCreateDto($this->bookingSessionService, $request);
-        if ($result instanceof Response) {
-            return $result;
+        try {
+            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
+        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
+            return $this->createBookingCreateFailureResponse($exception, false);
         }
-        $bookingCreateDto = $result;
 
         // Validate step access
-        if ($redirect = $this->validateStepAccess($bookingCreateDto, 4)) {
+        if (null !== $redirect = $this->validateStepAccess($bookingCreateDto, 4)) {
             return $redirect;
         }
 
diff --git a/src/Controller/Booking/Edit/IndexController.php b/src/Controller/Booking/Edit/IndexController.php
index 45b1ce2..cb5eb58 100644
--- a/src/Controller/Booking/Edit/IndexController.php
+++ b/src/Controller/Booking/Edit/IndexController.php
@@ -5,11 +5,11 @@ declare(strict_types=1);
 namespace App\Controller\Booking\Edit;
 
 use App\BusProNet\Model\Notification;
-use App\Controller\Booking\Traits\BookingExceptionHandlerTrait;
 use App\Entity\User;
 use App\Exception\TravelNotFoundException;
 use App\Form\BookingEditType;
 use App\Form\Model\BookingDto;
+use App\Model\BookingEditSubmissionResult;
 use App\Htmx\HxTrait;
 use App\Service\BookingChangeTracker;
 use App\Service\BookingEditContextFactory;
@@ -34,7 +34,6 @@ use Symfony\Component\Security\Http\Attribute\IsGranted;
  */
 class IndexController extends AbstractController
 {
-    use BookingExceptionHandlerTrait;
     use HxTrait;
 
     public function __construct(
@@ -43,7 +42,7 @@ class IndexController extends AbstractController
         private readonly BookingSessionManager $bookingSessionService,
         private readonly BookingChangeTracker $fingerprintService,
         private readonly BookingEditContextFactory $editContextFactory,
-        private readonly BookingEditSubmitter $submitService,
+        private readonly BookingEditSubmitter $formSubmitter,
     ) {
     }
 
@@ -53,32 +52,32 @@ class IndexController extends AbstractController
      * Clears any existing session data and API cache to ensure fresh data
      * is loaded, then redirects to the main edit page.
      */
-    #[Route('/bookings/{id}/edit/start', name: 'app_booking_edit_start', requirements: ['id' => '\d+'])]
+    #[Route('/bookings/{bookingId}/edit/start', name: 'app_booking_edit_start', requirements: ['bookingId' => '\d+'])]
     #[IsGranted('ROLE_USER')]
-    public function start(int $id, Request $request): Response
+    public function start(int $bookingId, Request $request): Response
     {
         /** @var User $user */
         $user = $this->getUser();
 
         $this->bookingSessionService->clearBookingDto($request, BookingDto::MODE_EDIT);
-        $this->dataLoader->invalidateBookingCache($id, $user);
+        $this->dataLoader->invalidateBookingCache($bookingId, $user);
 
-        return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+        return $this->redirectToRoute('app_booking_edit', ['bookingId' => $bookingId]);
     }
 
     /**
      * Display participant cards overview.
      */
-    #[Route('/bookings/{id}/edit', name: 'app_booking_edit', requirements: ['id' => '\d+'])]
+    #[Route('/bookings/{bookingId}/edit', name: 'app_booking_edit', requirements: ['bookingId' => '\d+'])]
     #[IsGranted('ROLE_USER')]
-    public function index(int $id, Request $request): Response
+    public function index(int $bookingId, Request $request): Response
     {
         /** @var User $user */
         $user = $this->getUser();
 
         // Load form data from session (or API on first load)
         try {
-            $bookingDto = $this->dataLoader->loadFormData($request, $id, $user);
+            $bookingDto = $this->dataLoader->loadFormData($request, $bookingId, $user);
         } catch (TravelNotFoundException) {
             $this->addFlash('error', 'Reisedaten sind nicht (mehr) verfügbar');
 
@@ -92,12 +91,12 @@ class IndexController extends AbstractController
         }
 
         // Show flash message if draft was restored
-        if (true === $this->dataLoader->wasDraftRestored()) {
+        if (true === $this->dataLoader->isDraftRestored()) {
             $this->addFlash('info', 'Dein zuvor gespeicherter Entwurf wurde wiederhergestellt.');
         }
 
         // Fetch booking data for display (surcharges, canceled status, etc.)
-        $bookingData = $this->dataLoader->fetchBookingData($id, $user);
+        $bookingData = $this->dataLoader->fetchBookingData($bookingId, $user);
         if (null === $bookingData || $bookingData instanceof Notification) {
             $this->addFlash('error', 'Buchungsdaten nicht (mehr) verfügbar');
 
@@ -110,7 +109,10 @@ class IndexController extends AbstractController
 
         // Handle form submission (clicking "Buchung aktualisieren")
         if ($form->isSubmitted() && $form->isValid()) {
-            return $this->submitService->handleSubmission($request, $bookingDto, $id, $user);
+            $submissionResult = $this->formSubmitter->handleSubmission($request, $bookingDto, $bookingId, $user);
+            $this->applySubmissionResultFlashes($submissionResult);
+
+            return $this->redirectToRoute('app_booking_edit', ['bookingId' => $bookingId]);
         }
 
         $bookingEditContext = $this->editContextFactory->createOverviewContext(
@@ -129,6 +131,39 @@ class IndexController extends AbstractController
         return $this->render('booking/edit/index.html.twig', $templateData);
     }
 
+    private function applySubmissionResultFlashes(BookingEditSubmissionResult $result): void
+    {
+        if (true === $result->immutableChangesReverted) {
+            $this->addFlash('info', 'Einige Änderungen wurden verworfen, da sie aktuell nicht mehr änderbar sind.');
+        }
+
+        switch ($result->status) {
+            case BookingEditSubmissionResult::STATUS_BOOKING_DATA_RELOAD_FAILED:
+                $this->addFlash('error', 'Buchungsdaten konnten vor dem Speichern nicht neu geladen werden');
+                break;
+            case BookingEditSubmissionResult::STATUS_NOTIFICATION_ERROR:
+                $this->addFlash('error', $result->message ?? 'Es ist ein Fehler in der Kommunikation mit dem Buchungssystem aufgetreten');
+                break;
+            case BookingEditSubmissionResult::STATUS_NOTIFICATION_INFO:
+                if (null !== $result->message && '' !== trim($result->message)) {
+                    $this->addFlash('info', $result->message);
+                }
+                break;
+            case BookingEditSubmissionResult::STATUS_SUCCESS:
+                $this->addFlash('success', 'Buchung erfolgreich aktualisiert');
+                break;
+            case BookingEditSubmissionResult::STATUS_UNSUCCESSFUL:
+                $this->addFlash('error', $result->message ?? 'Buchung konnte nicht aktualisiert werden');
+                break;
+            case BookingEditSubmissionResult::STATUS_TIMEOUT:
+                $this->addFlash('error', 'Die Anfrage hat zu lange gedauert. Bitte versuche es erneut.');
+                break;
+            case BookingEditSubmissionResult::STATUS_API_CLIENT_ERROR:
+                $this->addFlash('error', 'Es ist ein Fehler in der Kommunikation mit dem Buchungssystem aufgetreten');
+                break;
+        }
+    }
+
     /**
      * Reloads booking data from API, discarding all session changes.
      *
@@ -136,12 +171,12 @@ class IndexController extends AbstractController
      * POST: Clears session and redirects to reload the booking
      */
     #[Route(
-        path: '/bookings/{id}/edit/reload',
+        path: '/bookings/{bookingId}/edit/reload',
         name: 'app_booking_edit_reload',
-        requirements: ['id' => '\d+']
+        requirements: ['bookingId' => '\d+']
     )]
     #[IsGranted('ROLE_USER')]
-    public function reloadFromApi(int $id, Request $request): Response
+    public function reloadFromApi(int $bookingId, Request $request): Response
     {
         if (Request::METHOD_POST === $request->getMethod()) {
             // Clear session to discard all changes
@@ -150,15 +185,15 @@ class IndexController extends AbstractController
             // Delete draft since user explicitly chose to discard changes
             /** @var User $user */
             $user = $this->getUser();
-            $this->draftService->deleteDraft($user, $id);
+            $this->draftService->deleteDraft($user, $bookingId);
 
             $this->addFlash('success', 'Änderungen verworfen, Daten neu geladen');
 
-            return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+            return $this->redirectToRoute('app_booking_edit', ['bookingId' => $bookingId]);
         }
 
         return $this->render('booking/edit/modal_reload.html.twig', [
-            'bookingId' => $id,
+            'bookingId' => $bookingId,
         ]);
     }
 
@@ -169,12 +204,12 @@ class IndexController extends AbstractController
      * Shows a flash message informing about the saved draft.
      */
     #[Route(
-        path: '/bookings/{id}/edit/cancel',
+        path: '/bookings/{bookingId}/edit/cancel',
         name: 'app_booking_edit_cancel',
-        requirements: ['id' => '\d+']
+        requirements: ['bookingId' => '\d+']
     )]
     #[IsGranted('ROLE_USER')]
-    public function cancelEdit(int $id, Request $request): Response
+    public function cancelEdit(int $bookingId, Request $request): Response
     {
         // Clear session state
         $this->bookingSessionService->clearBookingDto($request, BookingDto::MODE_EDIT);
@@ -182,7 +217,7 @@ class IndexController extends AbstractController
         // Check if a draft exists to show appropriate message
         /** @var User $user */
         $user = $this->getUser();
-        $draft = $this->draftService->findDraft($user, $id);
+        $draft = $this->draftService->findDraft($user, $bookingId);
 
         if (null !== $draft) {
             $this->addFlash('info', 'Deine Änderungen wurden als Entwurf gespeichert.');
diff --git a/src/Controller/Booking/Edit/ParticipantController.php b/src/Controller/Booking/Edit/ParticipantController.php
index a2f7095..588bb07 100644
--- a/src/Controller/Booking/Edit/ParticipantController.php
+++ b/src/Controller/Booking/Edit/ParticipantController.php
@@ -41,12 +41,12 @@ class ParticipantController extends AbstractController
      * Edit single participant form.
      */
     #[Route(
-        path: '/bookings/{id}/edit/participants/{index}',
+        path: '/bookings/{bookingId}/edit/participants/{index}',
         name: 'app_booking_edit_participant',
-        requirements: ['id' => '\d+', 'index' => '\d+']
+        requirements: ['bookingId' => '\d+', 'index' => '\d+']
     )]
     #[IsGranted('ROLE_USER')]
-    public function editParticipant(int $id, int $index, Request $request): Response
+    public function editParticipant(int $bookingId, int $index, Request $request): Response
     {
         /** @var User $user */
         $user = $this->getUser();
@@ -56,12 +56,12 @@ class ParticipantController extends AbstractController
         if (null === $bookingDto) {
             $this->addFlash('error', 'Sitzung abgelaufen. Bitte neu laden.');
 
-            return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+            return $this->redirectToRoute('app_booking_edit', ['bookingId' => $bookingId]);
         }
 
         $this->participantFormSupportService->ensureParticipantExists($bookingDto, $index);
 
-        $bookingData = $this->dataLoader->fetchBookingData($id, $user);
+        $bookingData = $this->dataLoader->fetchBookingData($bookingId, $user);
         if (null === $bookingData || $bookingData instanceof Notification) {
             $this->addFlash('error', 'Buchungsdaten nicht (mehr) verfügbar');
 
@@ -71,7 +71,7 @@ class ParticipantController extends AbstractController
         if ($this->isParticipantCanceled($bookingData, $index)) {
             $this->addFlash('warning', 'Stornierte Teilnehmer können nicht bearbeitet werden');
 
-            return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+            return $this->redirectToRoute('app_booking_edit', ['bookingId' => $bookingId]);
         }
 
         $this->editContextFactory->prepareBookingDto($bookingDto);
@@ -90,10 +90,10 @@ class ParticipantController extends AbstractController
 
         if ($form->isSubmitted() && $form->isValid()) {
             $this->bookingSessionService->saveBookingDto($request, $bookingDto, BookingDto::MODE_EDIT);
-            $this->draftService->saveDraft($user, $id, $bookingDto);
+            $this->draftService->saveDraft($user, $bookingId, $bookingDto);
             $this->addNotificationsAsFlashMessages($notifications);
 
-            return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+            return $this->redirectToRoute('app_booking_edit', ['bookingId' => $bookingId]);
         }
 
         $context = $this->editContextFactory->createParticipantContext($bookingDto, $bookingData);
@@ -106,9 +106,9 @@ class ParticipantController extends AbstractController
             'summaryData' => $context->summaryData,
             'mutableData' => $context->mutableData,
             'refreshRouteName' => 'app_booking_edit_participant_refresh',
-            'refreshRouteParams' => ['id' => $id, 'index' => $index],
+            'refreshRouteParams' => ['bookingId' => $bookingId, 'index' => $index],
             'cancelRouteName' => 'app_booking_edit',
-            'cancelRouteParams' => ['id' => $id],
+            'cancelRouteParams' => ['bookingId' => $bookingId],
         ]);
     }
 
@@ -116,13 +116,13 @@ class ParticipantController extends AbstractController
      * HTMX endpoint for refreshing participant form without validation.
      */
     #[Route(
-        path: '/bookings/{id}/edit/participants/{index}/refresh',
+        path: '/bookings/{bookingId}/edit/participants/{index}/refresh',
         name: 'app_booking_edit_participant_refresh',
-        requirements: ['id' => '\d+', 'index' => '\d+'],
+        requirements: ['bookingId' => '\d+', 'index' => '\d+'],
         methods: ['POST']
     )]
     #[IsGranted('ROLE_USER')]
-    public function refreshParticipantForm(int $id, int $index, Request $request): Response
+    public function refreshParticipantForm(int $bookingId, int $index, Request $request): Response
     {
         /** @var User $user */
         $user = $this->getUser();
@@ -136,7 +136,7 @@ class ParticipantController extends AbstractController
         $this->participantFormSupportService->ensureParticipantExists($bookingDto, $index);
         $this->editContextFactory->prepareBookingDto($bookingDto);
 
-        $bookingData = $this->dataLoader->fetchBookingData($id, $user);
+        $bookingData = $this->dataLoader->fetchBookingData($bookingId, $user);
 
         $wrapper = $this->participantFormSupportService->createParticipantEditDto($bookingDto, $index);
 
@@ -165,9 +165,9 @@ class ParticipantController extends AbstractController
                 'summaryData' => $context->summaryData,
                 'mutableData' => $context->mutableData,
                 'refreshRouteName' => 'app_booking_edit_participant_refresh',
-                'refreshRouteParams' => ['id' => $id, 'index' => $index],
+                'refreshRouteParams' => ['bookingId' => $bookingId, 'index' => $index],
                 'cancelRouteName' => 'app_booking_edit',
-                'cancelRouteParams' => ['id' => $id],
+                'cancelRouteParams' => ['bookingId' => $bookingId],
             ]
         );
 
@@ -192,6 +192,6 @@ class ParticipantController extends AbstractController
 
     private function isParticipantCanceled(Booking $bookingData, int $index): bool
     {
-        return 'S' === ($bookingData->participantsStatus[$index] ?? null);
+        return Booking::STATUS_CANCELED === ($bookingData->participantsStatus[$index] ?? null);
     }
 }
diff --git a/src/Controller/Booking/Traits/BookingCreateTrait.php b/src/Controller/Booking/Traits/BookingCreateTrait.php
deleted file mode 100644
index b12f6c5..0000000
--- a/src/Controller/Booking/Traits/BookingCreateTrait.php
+++ /dev/null
@@ -1,67 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace App\Controller\Booking\Traits;
-
-use App\Form\Model\BookingDto;
-use Psr\Log\LoggerInterface;
-use Symfony\Component\HttpFoundation\RedirectResponse;
-
-/**
- * Provides common functionality for booking creation controllers.
- *
- * This trait contains shared validation and redirect logic used across
- * all booking creation steps to ensure consistent behavior and reduce
- * code duplication.
- */
-trait BookingCreateTrait
-{
-    /**
-     * Validates step access and returns redirect response if necessary.
-     *
-     * @return RedirectResponse|null Returns redirect response if validation fails, null if access is allowed
-     */
-    private function validateStepAccess(BookingDto $bookingCreateDto, int $expectedStep): ?RedirectResponse
-    {
-        // Allow access to current step or any previous step
-        if ($expectedStep > $bookingCreateDto->currentStep) {
-            $this->addFlash('error', 'Bitte erst die vorherigen Schritte abschließen.');
-
-            return $this->redirectToCurrentStep($bookingCreateDto);
-        }
-
-        return null;
-    }
-
-    /**
-     * Redirects to the current step based on the DTO's currentStep.
-     */
-    private function redirectToCurrentStep(BookingDto $bookingCreateDto): RedirectResponse
-    {
-        $route = match ($bookingCreateDto->currentStep) {
-            2 => 'app_booking_create_step_2',
-            3 => 'app_booking_create_step_3',
-            4 => 'app_booking_create_step_4',
-            default => 'app_booking_create_step_1',
-        };
-
-        return $this->redirectToRoute($route);
-    }
-
-    /**
-     * Handles API errors by logging and adding a flash message.
-     */
-    /**
-     * @param array<string, mixed> $context
-     */
-    private function handleApiError(
-        LoggerInterface $logger,
-        string $logMessage,
-        array $context,
-        string $flashMessage,
-    ): void {
-        $logger->error($logMessage, $context);
-        $this->addFlash('error', $flashMessage);
-    }
-}
diff --git a/src/Controller/Booking/Traits/BookingExceptionHandlerTrait.php b/src/Controller/Booking/Traits/BookingExceptionHandlerTrait.php
deleted file mode 100644
index 10945b0..0000000
--- a/src/Controller/Booking/Traits/BookingExceptionHandlerTrait.php
+++ /dev/null
@@ -1,55 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace App\Controller\Booking\Traits;
-
-use App\Exception\BookingSessionNotFoundException;
-use App\Exception\HotelNotInTravelException;
-use App\Exception\TravelNotFoundException;
-use App\Form\Model\BookingDto;
-use App\Service\BookingSessionManager;
-use Symfony\Component\HttpFoundation\RedirectResponse;
-use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpFoundation\Response;
-
-/**
- * Provides centralized exception handling for booking controllers.
- *
- * This trait contains common exception handling logic for booking operations
- * including user-friendly error messages and appropriate redirects.
- */
-trait BookingExceptionHandlerTrait
-{
-    /**
-     * Safely retrieves booking DTO with centralized exception handling.
-     *
-     * Handles all booking-related exceptions and provides appropriate user feedback
-     * by redirecting to the error page with flash messages.
-     */
-    protected function getOrCreateBookingCreateDto(BookingSessionManager $bookingSessionService, Request $request): BookingDto|RedirectResponse
-    {
-        try {
-            return $bookingSessionService->getOrCreateBookingCreateDto($request);
-        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $e) {
-            $this->addFlash('error', 'Deine Buchungssitzung ist abgelaufen. Bitte starte eine neue Buchung.');
-
-            return $this->redirectToRoute('app_booking_create_error');
-        }
-    }
-
-    /**
-     * Safely retrieves booking DTO for HTMX requests with lightweight error responses.
-     *
-     * Returns empty 400 responses for HTMX requests when exceptions occur,
-     * allowing the frontend to handle errors appropriately.
-     */
-    protected function getOrCreateBookingCreateDtoForHtmx(BookingSessionManager $bookingSessionService, Request $request): mixed
-    {
-        try {
-            return $bookingSessionService->getOrCreateBookingCreateDto($request);
-        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $e) {
-            return new Response('', 400);
-        }
-    }
-}
diff --git a/src/Model/BookingEditSubmissionResult.php b/src/Model/BookingEditSubmissionResult.php
new file mode 100644
index 0000000..9317606
--- /dev/null
+++ b/src/Model/BookingEditSubmissionResult.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Model;
+
+final readonly class BookingEditSubmissionResult
+{
+    public const string STATUS_BOOKING_DATA_RELOAD_FAILED = 'booking_data_reload_failed';
+    public const string STATUS_NOTIFICATION_ERROR = 'notification_error';
+    public const string STATUS_NOTIFICATION_INFO = 'notification_info';
+    public const string STATUS_SUCCESS = 'success';
+    public const string STATUS_UNSUCCESSFUL = 'unsuccessful';
+    public const string STATUS_TIMEOUT = 'timeout';
+    public const string STATUS_API_CLIENT_ERROR = 'api_client_error';
+
+    public function __construct(
+        public string $status,
+        public ?string $message = null,
+        public bool $immutableChangesReverted = false,
+    ) {
+    }
+}
diff --git a/src/Service/BookingEditDataLoader.php b/src/Service/BookingEditDataLoader.php
index 5da4e9d..1d1a058 100644
--- a/src/Service/BookingEditDataLoader.php
+++ b/src/Service/BookingEditDataLoader.php
@@ -27,7 +27,7 @@ class BookingEditDataLoader
 {
     public const string CACHE_TAG_USER_PREFIX = 'user_bookings_';
 
-    private bool $draftWasRestored = false;
+    private bool $draftRestored = false;
 
     public function __construct(
         private readonly ApiClient $apiClient,
@@ -48,9 +48,9 @@ class BookingEditDataLoader
      * This flag is reset on each call to loadFormData() and can be used
      * by the controller to show a flash message to the user.
      */
-    public function wasDraftRestored(): bool
+    public function isDraftRestored(): bool
     {
-        return $this->draftWasRestored;
+        return $this->draftRestored;
     }
 
     /**
@@ -71,7 +71,7 @@ class BookingEditDataLoader
      */
     public function loadFormData(Request $request, int $bookingId, User $user): ?BookingDto
     {
-        $this->draftWasRestored = false;
+        $this->draftRestored = false;
 
         $formData = $this->bookingSessionService->getBookingDto($request, BookingDto::MODE_EDIT);
 
@@ -154,7 +154,7 @@ class BookingEditDataLoader
         if (null !== $draft) {
             $applied = $this->draftService->applyDraftToDto($draft, $formData, $travelData);
             if (true === $applied) {
-                $this->draftWasRestored = true;
+                $this->draftRestored = true;
             }
         }
 
diff --git a/src/Service/BookingEditSubmitter.php b/src/Service/BookingEditSubmitter.php
index c486319..b99dff0 100644
--- a/src/Service/BookingEditSubmitter.php
+++ b/src/Service/BookingEditSubmitter.php
@@ -9,12 +9,10 @@ use App\BusProNet\Exception\ApiClientException;
 use App\BusProNet\Exception\TimeoutException;
 use App\BusProNet\Model\Notification;
 use App\Entity\User;
+use App\Model\BookingEditSubmissionResult;
 use App\Form\Model\BookingDto;
 use Psr\Log\LoggerInterface;
-use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpFoundation\Session\FlashBagAwareSessionInterface;
-use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
 /**
  * Handles the final booking edit submission workflow.
@@ -28,12 +26,11 @@ class BookingEditSubmitter
         private readonly TravelDataProvider $travelDataService,
         private readonly BookingEditSubmitGuard $submitGuard,
         private readonly BookingSessionManager $bookingSessionService,
-        private readonly UrlGeneratorInterface $urlGenerator,
         private readonly LoggerInterface $logger,
     ) {
     }
 
-    public function handleSubmission(Request $request, BookingDto $bookingDto, int $bookingId, User $user): RedirectResponse
+    public function handleSubmission(Request $request, BookingDto $bookingDto, int $bookingId, User $user): BookingEditSubmissionResult
     {
         $email = $user->getEmail();
 
@@ -45,14 +42,15 @@ class BookingEditSubmitter
         $this->dataLoader->invalidateBookingCache($bookingId, $user);
         $freshBookingData = $this->dataLoader->fetchBookingData($bookingId, $user);
         if (null === $freshBookingData || $freshBookingData instanceof Notification) {
-            $this->addFlash($request, 'error', 'Buchungsdaten konnten vor dem Speichern nicht neu geladen werden');
             $this->logger->warning('Failed to refresh booking before update submission', [
                 'email' => $email,
                 'booking_id' => $bookingId,
                 'has_notification' => $freshBookingData instanceof Notification,
             ]);
 
-            return $this->redirectToEdit($bookingId);
+            return new BookingEditSubmissionResult(
+                BookingEditSubmissionResult::STATUS_BOOKING_DATA_RELOAD_FAILED,
+            );
         }
 
         $bookingDto->booking = $freshBookingData;
@@ -68,66 +66,69 @@ class BookingEditSubmitter
         $immutableChangesReverted = $this->submitGuard->reconcileImmutableCategories($bookingDto, $freshBookingData);
         if (true === $immutableChangesReverted) {
             $this->bookingSessionService->saveBookingDto($request, $bookingDto, BookingDto::MODE_EDIT);
-            $this->addFlash($request, 'info', 'Einige Änderungen wurden verworfen, da sie aktuell nicht mehr änderbar sind.');
         }
 
         try {
             $response = $this->apiClient->updateBooking($bookingDto, true);
             if ($response instanceof Notification) {
-                if (true === $response->isError()) {
-                    $this->addFlash($request, 'error', $response->message);
-                } else {
-                    $this->addFlash($request, 'info', $response->message);
-                }
                 $this->logger->error('Booking update not successful', [
                     'email' => $email,
                     'booking_id' => $bookingId,
                     'message' => $response->message,
                 ]);
-            } elseif (true === $response->success) {
+                return new BookingEditSubmissionResult(
+                    true === $response->isError()
+                        ? BookingEditSubmissionResult::STATUS_NOTIFICATION_ERROR
+                        : BookingEditSubmissionResult::STATUS_NOTIFICATION_INFO,
+                    $response->message,
+                    $immutableChangesReverted,
+                );
+            }
+
+            if (true === $response->success) {
                 $this->dataLoader->invalidateBookingCache($bookingId, $user);
                 $this->bookingSessionService->clearBookingDto($request, BookingDto::MODE_EDIT);
                 $this->draftService->deleteDraft($user, $bookingId);
-
-                $this->addFlash($request, 'success', 'Buchung erfolgreich aktualisiert');
                 $this->logger->info('Booking update successful', [
                     'email' => $email,
                     'booking_id' => $bookingId,
                 ]);
 
-                return $this->redirectToEdit($bookingId);
-            } else {
-                $this->addFlash($request, 'error', $response->status ?? 'Buchung konnte nicht aktualisiert werden');
-                $this->logger->warning('Booking update returned unsuccessful status', [
-                    'email' => $email,
-                    'booking_id' => $bookingId,
-                    'status' => $response->status,
-                    'valid' => $response->valid,
-                ]);
+                return new BookingEditSubmissionResult(
+                    BookingEditSubmissionResult::STATUS_SUCCESS,
+                    null,
+                    $immutableChangesReverted,
+                );
             }
+
+            $this->logger->warning('Booking update returned unsuccessful status', [
+                'email' => $email,
+                'booking_id' => $bookingId,
+                'status' => $response->status,
+                'valid' => $response->valid,
+            ]);
+
+            return new BookingEditSubmissionResult(
+                BookingEditSubmissionResult::STATUS_UNSUCCESSFUL,
+                $response->status ?? 'Buchung konnte nicht aktualisiert werden',
+                $immutableChangesReverted,
+            );
         } catch (TimeoutException) {
-            $this->addFlash($request, 'error', 'Die Anfrage hat zu lange gedauert. Bitte versuchen Sie es erneut.');
             $this->logger->error('Booking update timeout', [
                 'email' => $email,
                 'booking_id' => $bookingId,
             ]);
+            return new BookingEditSubmissionResult(
+                BookingEditSubmissionResult::STATUS_TIMEOUT,
+                null,
+                $immutableChangesReverted,
+            );
         } catch (ApiClientException) {
-            $this->addFlash($request, 'error', 'Es ist ein Fehler in der Kommunikation mit dem Buchungssystem aufgetreten');
+            return new BookingEditSubmissionResult(
+                BookingEditSubmissionResult::STATUS_API_CLIENT_ERROR,
+                null,
+                $immutableChangesReverted,
+            );
         }
-
-        return $this->redirectToEdit($bookingId);
-    }
-
-    private function addFlash(Request $request, string $type, string $message): void
-    {
-        $session = $request->getSession();
-        if ($session instanceof FlashBagAwareSessionInterface) {
-            $session->getFlashBag()->add($type, $message);
-        }
-    }
-
-    private function redirectToEdit(int $bookingId): RedirectResponse
-    {
-        return new RedirectResponse($this->urlGenerator->generate('app_booking_edit', ['id' => $bookingId]));
     }
 }
diff --git a/templates/booking/_participant_card.html.twig b/templates/booking/_participant_card.html.twig
index 74d0f28..0ae987b 100644
--- a/templates/booking/_participant_card.html.twig
+++ b/templates/booking/_participant_card.html.twig
@@ -10,7 +10,7 @@
 
 {# Build edit URL for linking #}
 {% if mode == 'edit' %}
-    {% set editUrl = path('app_booking_edit_participant', {id: bookingId, index: index}) %}
+    {% set editUrl = path('app_booking_edit_participant', {bookingId: bookingId, index: index}) %}
 {% else %}
     {% set editUrl = path('app_booking_create_step_2_participant', {index: index}) %}
 {% endif %}
diff --git a/templates/booking/edit/index.html.twig b/templates/booking/edit/index.html.twig
index 63f0349..09d254c 100644
--- a/templates/booking/edit/index.html.twig
+++ b/templates/booking/edit/index.html.twig
@@ -32,7 +32,7 @@
                     </h1>
                     {% if bookingEditContext.isDirty %}
                         <button type="button"
-                                hx-get="{{ path('app_booking_edit_reload', {id: bookingEditContext.bookingData.id}) }}"
+                        hx-get="{{ path('app_booking_edit_reload', {bookingId: bookingEditContext.bookingData.id}) }}"
                                 hx-target="body"
                                 hx-swap="beforeend"
                                 class="button button--small button--secondary">
@@ -85,7 +85,7 @@
         {# Fixed footer #}
         <div class="shrink-0 bg-primary-dark px-4 lg:px-8 py-2 lg:py-4 z-20">
             <div class="flex justify-between" hx-disinherit="*">
-                <a href="{{ bookingEditContext.isDirty ? path('app_booking_edit_cancel', {id: bookingEditContext.bookingData.id}) : path('app_bookings') }}"
+                <a href="{{ bookingEditContext.isDirty ? path('app_booking_edit_cancel', {bookingId: bookingEditContext.bookingData.id}) : path('app_bookings') }}"
                    class="inline-flex items-center justify-center bg-gray-200 rounded-md w-8 h-8 md:w-10 md:h-10">
                     <svg class="w-6 h-6 md:w-8 md:h-8" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 256"><rect width="256" height="256" fill="none"/><line x1="200" y1="56" x2="56" y2="200" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/><line x1="200" y1="200" x2="56" y2="56" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/></svg>
                 </a>
diff --git a/templates/booking/edit/modal_reload.html.twig b/templates/booking/edit/modal_reload.html.twig
index c5ecd85..dd9fe19 100644
--- a/templates/booking/edit/modal_reload.html.twig
+++ b/templates/booking/edit/modal_reload.html.twig
@@ -8,7 +8,7 @@
     </div>
     <div class="flex justify-between">
         <button type="button"
-                hx-post="{{ path('app_booking_edit_reload', {id: bookingId}) }}"
+                hx-post="{{ path('app_booking_edit_reload', {bookingId: bookingId}) }}"
                 hx-target="body"
                 class="button button--small button--primary">
             Ja
diff --git a/templates/booking/edit/participant.html.twig b/templates/booking/edit/participant.html.twig
index 24520e9..80777ec 100644
--- a/templates/booking/edit/participant.html.twig
+++ b/templates/booking/edit/participant.html.twig
@@ -43,7 +43,7 @@
         </div>
         <div class="shrink-0 bg-primary-dark px-4 lg:px-8 py-2 lg:py-4 z-20">
             <div class="flex justify-between">
-                <a href="{{ path('app_booking_edit', {id: bookingEditContext.bookingData.id}) }}"
+                <a href="{{ path('app_booking_edit', {bookingId: bookingEditContext.bookingData.id}) }}"
                    class="inline-flex items-center justify-center bg-gray-200 rounded-md w-8 h-8 md:w-10 md:h-10"
                    {{ qa_attribute('btn-cancel') }}>
                     <svg class="w-6 h-6 md:w-8 md:h-8" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 256"><rect width="256" height="256" fill="none"/><line x1="200" y1="56" x2="56" y2="200" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/><line x1="200" y1="200" x2="56" y2="56" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/></svg>
diff --git a/templates/booking/index.html.twig b/templates/booking/index.html.twig
index e41b47f..a1e25f3 100644
--- a/templates/booking/index.html.twig
+++ b/templates/booking/index.html.twig
@@ -73,7 +73,7 @@
                             </table>
                             <div class="flex space-x-2">
                                 {% if booking.editable %}
-                                    <a href="{{ path('app_booking_edit_start', { 'id': booking.id }) }}"
+                                    <a href="{{ path('app_booking_edit_start', { bookingId: booking.id }) }}"
                                        class="button button--primary button--small"
                                        title="Buchung bearbeiten">
                                         <svg class="w-6 h-6" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 256"><rect width="256" height="256" fill="none"/><path d="M92.69,216H48a8,8,0,0,1-8-8V163.31a8,8,0,0,1,2.34-5.65L165.66,34.34a8,8,0,0,1,11.31,0L221.66,79a8,8,0,0,1,0,11.31L98.34,213.66A8,8,0,0,1,92.69,216Z" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/><line x1="136" y1="64" x2="192" y2="120" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/><line x1="164" y1="92" x2="68" y2="188" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/><line x1="95.49" y1="215.49" x2="40.51" y2="160.51" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="16"/></svg>
diff --git a/tests/Controller/Booking/Edit/IndexControllerTest.php b/tests/Controller/Booking/Edit/IndexControllerTest.php
new file mode 100644
index 0000000..7c432f8
--- /dev/null
+++ b/tests/Controller/Booking/Edit/IndexControllerTest.php
@@ -0,0 +1,257 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Booking\Edit;
+
+use App\BusProNet\Model\Booking;
+use App\BusProNet\Model\Travel;
+use App\Controller\Booking\Edit\IndexController;
+use App\Entity\User;
+use App\Form\Model\BookingDto;
+use App\Model\BookingEditSubmissionResult;
+use App\Service\BookingChangeTracker;
+use App\Service\BookingEditContextFactory;
+use App\Service\BookingEditDataLoader;
+use App\Service\BookingEditDraftManager;
+use App\Service\BookingEditSubmitter;
+use App\Service\BookingSessionManager;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Form\FormInterface;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Security\Core\User\UserInterface;
+
+class IndexControllerTest extends TestCase
+{
+    public function testIndexAppliesSubmissionResultFlashesAndRedirectsBackToEditPage(): void
+    {
+        $this->assertSubmissionResultFlashes(
+            new BookingEditSubmissionResult(
+                BookingEditSubmissionResult::STATUS_SUCCESS,
+                null,
+                true
+            ),
+            [
+                ['info', 'Einige Änderungen wurden verworfen, da sie aktuell nicht mehr änderbar sind.'],
+                ['success', 'Buchung erfolgreich aktualisiert'],
+            ],
+        );
+    }
+
+    /**
+     * @dataProvider submissionResultProvider
+     *
+     * @param array<int, array{0: string, 1: string}> $expectedFlashes
+     * @phpstan-param array<int, array{0: string, 1: string}> $expectedFlashes
+     */
+    public function testIndexAppliesErrorSubmissionResultFlashesAndRedirectsBackToEditPage(
+        BookingEditSubmissionResult $submissionResult,
+        array $expectedFlashes,
+    ): void {
+        $this->assertSubmissionResultFlashes($submissionResult, $expectedFlashes);
+    }
+
+    /**
+     * @return array<string, array{0: BookingEditSubmissionResult, 1: array<int, array{0: string, 1: string}>}>
+     */
+    public static function submissionResultProvider(): array
+    {
+        return [
+            'notification error' => [
+                new BookingEditSubmissionResult(
+                    BookingEditSubmissionResult::STATUS_NOTIFICATION_ERROR,
+                    'BPN-FAIL',
+                    false
+                ),
+                [
+                    ['error', 'BPN-FAIL'],
+                ],
+            ],
+            'timeout' => [
+                new BookingEditSubmissionResult(
+                    BookingEditSubmissionResult::STATUS_TIMEOUT,
+                    null,
+                    false
+                ),
+                [
+                    ['error', 'Die Anfrage hat zu lange gedauert. Bitte versuche es erneut.'],
+                ],
+            ],
+            'reload failed' => [
+                new BookingEditSubmissionResult(
+                    BookingEditSubmissionResult::STATUS_BOOKING_DATA_RELOAD_FAILED,
+                    null,
+                    false
+                ),
+                [
+                    ['error', 'Buchungsdaten konnten vor dem Speichern nicht neu geladen werden'],
+                ],
+            ],
+        ];
+    }
+
+    private function createUser(): User
+    {
+        return new User('tester@example.com');
+    }
+
+    private function createBookingDto(): BookingDto
+    {
+        $travel = new Travel();
+        $travel->id = 1234;
+
+        $bookingDto = new BookingDto($travel, 77);
+        $bookingDto->booking = new Booking();
+        $bookingDto->booking->id = 42;
+
+        return $bookingDto;
+    }
+
+    private function createBooking(): Booking
+    {
+        $booking = new Booking();
+        $booking->id = 42;
+        $booking->dateId = 1234;
+
+        return $booking;
+    }
+
+    /**
+     * @param array<int, array{0: string, 1: string}> $expectedFlashes
+     */
+    private function assertSubmissionResultFlashes(
+        BookingEditSubmissionResult $submissionResult,
+        array $expectedFlashes,
+    ): void {
+        $request = Request::create('/bookings/42/edit', 'POST');
+        $user = $this->createUser();
+        $bookingDto = $this->createBookingDto();
+        $bookingData = $this->createBooking();
+        $form = $this->createMock(FormInterface::class);
+
+        $form->expects($this->once())
+            ->method('handleRequest')
+            ->with($request)
+            ->willReturnSelf();
+        $form->expects($this->once())
+            ->method('isSubmitted')
+            ->willReturn(true);
+        $form->expects($this->once())
+            ->method('isValid')
+            ->willReturn(true);
+
+        $dataLoader = $this->createMock(BookingEditDataLoader::class);
+        $dataLoader->expects($this->once())
+            ->method('loadFormData')
+            ->with($request, 42, $user)
+            ->willReturn($bookingDto);
+        $dataLoader->expects($this->once())
+            ->method('fetchBookingData')
+            ->with(42, $user)
+            ->willReturn($bookingData);
+        $dataLoader->expects($this->once())
+            ->method('isDraftRestored');
+
+        $submitter = $this->createMock(BookingEditSubmitter::class);
+        $submitter->expects($this->once())
+            ->method('handleSubmission')
+            ->with($request, $bookingDto, 42, $user)
+            ->willReturn($submissionResult);
+
+        $controller = new TestableIndexController(
+            $dataLoader,
+            $this->createMock(BookingEditDraftManager::class),
+            $this->createMock(BookingSessionManager::class),
+            $this->createMock(BookingChangeTracker::class),
+            $this->createMock(BookingEditContextFactory::class),
+            $submitter,
+            $user,
+            $form,
+        );
+
+        $response = $controller->index(42, $request);
+
+        $this->assertInstanceOf(RedirectResponse::class, $response);
+        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
+        $this->assertSame($expectedFlashes, $controller->flashes);
+    }
+}
+
+final class TestableIndexController extends IndexController
+{
+    /**
+     * @var array<int, array{string, mixed}>
+     */
+    public array $flashes = [];
+
+    /**
+     * @var FormInterface<mixed>
+     */
+    private readonly FormInterface $form;
+
+    /**
+     * @param FormInterface<mixed> $form
+     */
+    public function __construct(
+        BookingEditDataLoader $dataLoader,
+        BookingEditDraftManager $draftService,
+        BookingSessionManager $bookingSessionService,
+        BookingChangeTracker $fingerprintService,
+        BookingEditContextFactory $editContextFactory,
+        BookingEditSubmitter $formSubmitter,
+        private readonly User $user,
+        FormInterface $form,
+    ) {
+        $this->form = $form;
+
+        parent::__construct(
+            $dataLoader,
+            $draftService,
+            $bookingSessionService,
+            $fingerprintService,
+            $editContextFactory,
+            $formSubmitter,
+        );
+    }
+
+    protected function getUser(): UserInterface
+    {
+        return $this->user;
+    }
+
+    /**
+     * @return FormInterface<mixed>
+     */
+    protected function createForm(string $type, mixed $data = null, array $options = []): FormInterface
+    {
+        return $this->form;
+    }
+
+    protected function addFlash(string $type, mixed $message): void
+    {
+        $this->flashes[] = [$type, $message];
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function redirectToRoute(string $route, array $parameters = [], int $status = 302): RedirectResponse
+    {
+        $location = match ($route) {
+            'app_booking_edit' => '/bookings/'.$parameters['bookingId'].'/edit',
+            default => '/'.$route,
+        };
+
+        return new RedirectResponse($location, $status);
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function render(string $view, array $parameters = [], ?Response $response = null): Response
+    {
+        throw new \LogicException('Render should not be called in this test.');
+    }
+}
diff --git a/tests/Service/BookingEditSubmitterTest.php b/tests/Service/BookingEditSubmitterTest.php
index 1171b10..29cb02e 100644
--- a/tests/Service/BookingEditSubmitterTest.php
+++ b/tests/Service/BookingEditSubmitterTest.php
@@ -12,6 +12,7 @@ use App\BusProNet\Model\Notification;
 use App\BusProNet\Model\Travel;
 use App\Entity\User;
 use App\Form\Model\BookingDto;
+use App\Model\BookingEditSubmissionResult;
 use App\Service\BookingEditDataLoader;
 use App\Service\BookingEditDraftManager;
 use App\Service\BookingEditSubmitGuard;
@@ -23,11 +24,10 @@ use Psr\Log\LoggerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Session\Session;
 use Symfony\Component\HttpFoundation\Session\Storage\MockArraySessionStorage;
-use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
 class BookingEditSubmitterTest extends TestCase
 {
-    public function testHandleSubmissionReturnsRedirectWhenFreshBookingDataCannotBeLoaded(): void
+    public function testHandleSubmissionReturnsResultWhenFreshBookingDataCannotBeLoaded(): void
     {
         $request = $this->createRequestWithSession();
         $user = $this->createUser();
@@ -46,22 +46,18 @@ class BookingEditSubmitterTest extends TestCase
             dataLoader: $dataLoader,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame(
-            ['Buchungsdaten konnten vor dem Speichern nicht neu geladen werden'],
-            $request->getSession()->getFlashBag()->get('error')
-        );
+        $this->assertSame(BookingEditSubmissionResult::STATUS_BOOKING_DATA_RELOAD_FAILED, $result->status);
+        $this->assertFalse($result->immutableChangesReverted);
     }
 
     /**
      * @dataProvider updateFailureProvider
      */
-    public function testHandleSubmissionReturnsRedirectWhenUpdateThrows(
+    public function testHandleSubmissionReturnsResultWhenUpdateThrows(
         \Throwable $exception,
-        string $expectedFlashType,
-        string $expectedFlashMessage,
+        string $expectedStatus,
     ): void {
         $request = $this->createRequestWithSession();
         $user = $this->createUser();
@@ -104,13 +100,14 @@ class BookingEditSubmitterTest extends TestCase
             submitGuard: $submitGuard,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame([$expectedFlashMessage], $request->getSession()->getFlashBag()->get($expectedFlashType));
+        $this->assertSame($expectedStatus, $result->status);
+        $this->assertNull($result->message);
+        $this->assertFalse($result->immutableChangesReverted);
     }
 
-    public function testHandleSubmissionReturnsRedirectWhenUpdateIsUnsuccessful(): void
+    public function testHandleSubmissionReturnsResultWhenUpdateIsUnsuccessful(): void
     {
         $request = $this->createRequestWithSession();
         $user = $this->createUser();
@@ -156,20 +153,21 @@ class BookingEditSubmitterTest extends TestCase
             submitGuard: $submitGuard,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame(['BPN-FAIL'], $request->getSession()->getFlashBag()->get('error'));
+        $this->assertSame(BookingEditSubmissionResult::STATUS_UNSUCCESSFUL, $result->status);
+        $this->assertSame('BPN-FAIL', $result->message);
+        $this->assertFalse($result->immutableChangesReverted);
     }
 
     public function testHandleSubmissionStoresInfoForNonErrorNotification(): void
     {
-        $this->assertNotificationFlash(new Notification(650, 'Alles gut'), 'info');
+        $this->assertNotificationResult(new Notification(650, 'Alles gut'), 'info');
     }
 
     public function testHandleSubmissionStoresErrorForErrorNotification(): void
     {
-        $this->assertNotificationFlash(new Notification(500, 'Kaputt'), 'error');
+        $this->assertNotificationResult(new Notification(500, 'Kaputt'), 'error');
     }
 
     public function testHandleSubmissionClearsSessionAndDraftOnSuccessfulUpdate(): void
@@ -231,10 +229,10 @@ class BookingEditSubmitterTest extends TestCase
             bookingSessionService: $bookingSessionService,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame(['Buchung erfolgreich aktualisiert'], $request->getSession()->getFlashBag()->get('success'));
+        $this->assertSame(BookingEditSubmissionResult::STATUS_SUCCESS, $result->status);
+        $this->assertFalse($result->immutableChangesReverted);
         $this->assertSame($freshBookingData, $bookingDto->booking);
     }
 
@@ -298,32 +296,31 @@ class BookingEditSubmitterTest extends TestCase
             bookingSessionService: $bookingSessionService,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame(['Einige Änderungen wurden verworfen, da sie aktuell nicht mehr änderbar sind.'], $request->getSession()->getFlashBag()->get('info'));
-        $this->assertSame(['Buchung erfolgreich aktualisiert'], $request->getSession()->getFlashBag()->get('success'));
+        $this->assertSame(BookingEditSubmissionResult::STATUS_SUCCESS, $result->status);
+        $this->assertTrue($result->immutableChangesReverted);
     }
 
-    public function testHandleSubmissionReturnsRedirectOnTimeout(): void
+    public function testHandleSubmissionReturnsResultOnTimeout(): void
     {
-        $this->assertExceptionFlash(new TimeoutException('slow'), 'Die Anfrage hat zu lange gedauert. Bitte versuchen Sie es erneut.');
+        $this->assertExceptionResult(new TimeoutException('slow'), BookingEditSubmissionResult::STATUS_TIMEOUT);
     }
 
-    public function testHandleSubmissionReturnsRedirectOnApiClientException(): void
+    public function testHandleSubmissionReturnsResultOnApiClientException(): void
     {
-        $this->assertExceptionFlash(new ApiClientException('boom'), 'Es ist ein Fehler in der Kommunikation mit dem Buchungssystem aufgetreten');
+        $this->assertExceptionResult(new ApiClientException('boom'), BookingEditSubmissionResult::STATUS_API_CLIENT_ERROR);
     }
 
     public static function updateFailureProvider(): array
     {
         return [
-            'timeout' => [new TimeoutException('slow'), 'error', 'Die Anfrage hat zu lange gedauert. Bitte versuchen Sie es erneut.'],
-            'api-client' => [new ApiClientException('boom'), 'error', 'Es ist ein Fehler in der Kommunikation mit dem Buchungssystem aufgetreten'],
+            'timeout' => [new TimeoutException('slow'), BookingEditSubmissionResult::STATUS_TIMEOUT],
+            'api-client' => [new ApiClientException('boom'), BookingEditSubmissionResult::STATUS_API_CLIENT_ERROR],
         ];
     }
 
-    private function assertNotificationFlash(Notification $notification, string $expectedType): void
+    private function assertNotificationResult(Notification $notification, string $expectedType): void
     {
         $request = $this->createRequestWithSession();
         $user = $this->createUser();
@@ -366,13 +363,14 @@ class BookingEditSubmitterTest extends TestCase
             submitGuard: $submitGuard,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame([$notification->message], $request->getSession()->getFlashBag()->get($expectedType));
+        $this->assertSame($this->resolveExpectedStatus($expectedType), $result->status);
+        $this->assertSame($notification->message, $result->message);
+        $this->assertFalse($result->immutableChangesReverted);
     }
 
-    private function assertExceptionFlash(\Throwable $exception, string $expectedMessage): void
+    private function assertExceptionResult(\Throwable $exception, string $expectedStatus): void
     {
         $request = $this->createRequestWithSession();
         $user = $this->createUser();
@@ -415,10 +413,11 @@ class BookingEditSubmitterTest extends TestCase
             submitGuard: $submitGuard,
         );
 
-        $response = $service->handleSubmission($request, $bookingDto, 42, $user);
+        $result = $service->handleSubmission($request, $bookingDto, 42, $user);
 
-        $this->assertSame('/bookings/42/edit', $response->headers->get('Location'));
-        $this->assertSame([$expectedMessage], $request->getSession()->getFlashBag()->get('error'));
+        $this->assertSame($expectedStatus, $result->status);
+        $this->assertNull($result->message);
+        $this->assertFalse($result->immutableChangesReverted);
     }
 
     private function createService(
@@ -436,7 +435,6 @@ class BookingEditSubmitterTest extends TestCase
             $travelDataService ?? $this->createMock(TravelDataProvider::class),
             $submitGuard ?? $this->createMock(BookingEditSubmitGuard::class),
             $bookingSessionService ?? $this->createMock(BookingSessionManager::class),
-            $this->createUrlGenerator(),
             $this->createMock(LoggerInterface::class),
         );
     }
@@ -470,13 +468,13 @@ class BookingEditSubmitterTest extends TestCase
         return $request;
     }
 
-    private function createUrlGenerator(): UrlGeneratorInterface
+    private function resolveExpectedStatus(string $expectedType): string
     {
-        $urlGenerator = $this->createMock(UrlGeneratorInterface::class);
-        $urlGenerator->method('generate')
-            ->with('app_booking_edit', ['id' => 42])
-            ->willReturn('/bookings/42/edit');
-
-        return $urlGenerator;
+        return match ($expectedType) {
+            'error' => BookingEditSubmissionResult::STATUS_NOTIFICATION_ERROR,
+            'info' => BookingEditSubmissionResult::STATUS_NOTIFICATION_INFO,
+            default => $expectedType,
+        };
     }
+
 }