diff --git a/src/BusProNet/DataProcessor/BookingDataProcessor.php b/src/BusProNet/DataProcessor/BookingDataProcessor.php
index 4f89656..e11504c 100644
--- a/src/BusProNet/DataProcessor/BookingDataProcessor.php
+++ b/src/BusProNet/DataProcessor/BookingDataProcessor.php
@@ -9,13 +9,14 @@ use App\BusProNet\Model\Booking;
 use App\BusProNet\Model\Insurance;
 use App\BusProNet\Model\Travel;
 use App\BusProNet\Utility\DirectionMapper;
-use App\BusProNet\XmlLoader\AgencyLoader;
 use App\Form\Model\BankAccountDto;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
 use App\Form\Model\RoomSelectionDto;
+use App\Service\ApplicantInsuranceCascade;
 use App\Service\BookingPriceCalculator;
 use App\Service\InsuranceManager;
+
 use function Symfony\Component\String\u;
 
 /**
@@ -34,6 +35,7 @@ class BookingDataProcessor
         private readonly ParticipantServiceProcessor $serviceProcessor,
         private readonly BookingPayloadBuilder $payloadBuilder,
         private readonly PersonalDataSynchronizer $personalDataSynchronizer,
+        private readonly ApplicantInsuranceCascade $applicantInsuranceCascade,
     ) {
     }
 
@@ -303,7 +305,7 @@ class BookingDataProcessor
     public function createUpdateRequestPayload(?BookingDto $formData): array
     {
         // Apply bulk or family insurance if applicable (modifies DTO in place)
-        $this->applyApplicantInsuranceToParticipants($formData);
+        $this->applicantInsuranceCascade->apply($formData);
 
         $bookingData = $formData->booking;
         $travelData = $formData->travel;
@@ -372,7 +374,7 @@ class BookingDataProcessor
         $this->reconcileInsuranceEligibility($bookingDto);
 
         // Apply bulk or family insurance if applicable (modifies DTO in place)
-        $this->applyApplicantInsuranceToParticipants($bookingDto);
+        $this->applicantInsuranceCascade->apply($bookingDto);
 
         return $this->payloadBuilder->buildCreatePayload($bookingDto, $bookingType);
     }
@@ -453,81 +455,4 @@ class BookingDataProcessor
 
         return false;
     }
-
-    /**
-     * Applies the applicant's insurance to other participants if their selection requires it.
-     *
-     * Runs when either:
-     * - Bulk insurance is active (applicant's bulkInsuranceBooking = true): assigns the
-     *   applicant's insurance TYPE to all dependent participants with automatic price tier
-     *   adjustment based on each participant's individual cost.
-     * - The applicant selected a family insurance: family insurance covers the whole family
-     *   under a single policy, so dependents must never hold their own insurance, regardless
-     *   of whether the bulk checkbox was checked.
-     *
-     * IMPORTANT: In edit mode, non-family bulk insurance only applies to participants who:
-     * 1. Currently have NO insurance assigned (insurance === null)
-     * 2. OR whose insurance was already assigned via previous bulk operation
-     *
-     * This prevents overriding individually selected insurances that are locked. Family
-     * insurance is exempt from this protection: dependents can never legitimately hold
-     * their own policy alongside it, so their insurance is always cleared, in edit mode too.
-     *
-     * @param BookingDto $bookingDto The booking DTO (create or edit flow)
-     */
-    private function applyApplicantInsuranceToParticipants(BookingDto $bookingDto): void
-    {
-        $applicant = $bookingDto->getParticipant(0);
-
-        if (null === $applicant || null === $applicant->insurance) {
-            return;
-        }
-
-        $isFamilyInsurance = true === $applicant->insurance->familyInsurance;
-
-        // Check if bulk insurance is enabled OR the applicant's selection is a family
-        // insurance (which always applies to dependents, independent of the bulk checkbox)
-        if (false === $applicant->bulkInsuranceBooking && false === $isFamilyInsurance) {
-            return;
-        }
-
-        // Get selectable (non-complementary) insurances with caching
-        $selectableInsurances = $this->insuranceService->getSelectableInsurances($bookingDto->travel);
-
-        // Calculate travel prices for all participants (excluding insurance)
-        $participantPrices = [];
-        foreach ($bookingDto->getParticipants() as $index => $participant) {
-            $participantPrices[$index] = $this->priceCalculatorService->calculateIndividualParticipantPriceExcludingInsurance($bookingDto, $index);
-        }
-
-        // Use InsuranceManager for proper type-based assignment with price tier matching
-        $assignments = $this->insuranceService->batchAssignInsuranceToParticipants(
-            $selectableInsurances,
-            $applicant->insurance,
-            $bookingDto,
-            $participantPrices
-        );
-
-        // Apply assignments to all participants; for non-family insurance skip the applicant
-        // (they already hold the insurance they selected themselves)
-        foreach ($assignments as $index => $insurance) {
-            if (0 === $index && false === $isFamilyInsurance) {
-                continue;
-            }
-
-            $participant = $bookingDto->getParticipant($index);
-            if (null === $participant) {
-                continue;
-            }
-
-            // In edit mode: non-family bulk assignment must not overwrite an individually
-            // locked insurance. Family insurance always overrides, since dependents can
-            // never legitimately keep their own policy alongside it.
-            if (BookingDto::MODE_EDIT === $bookingDto->getMode() && false === $isFamilyInsurance && null !== $participant->insurance) {
-                continue; // Skip participants with existing insurance assignment
-            }
-
-            $participant->insurance = $insurance;
-        }
-    }
 }
diff --git a/src/Controller/Booking/Create/Step2ParticipantController.php b/src/Controller/Booking/Create/Step2ParticipantController.php
index 1ce8a01..0e6ca55 100644
--- a/src/Controller/Booking/Create/Step2ParticipantController.php
+++ b/src/Controller/Booking/Create/Step2ParticipantController.php
@@ -7,6 +7,7 @@ namespace App\Controller\Booking\Create;
 use App\Form\BookingParticipantType;
 use App\Form\Model\BookingDto;
 use App\Htmx\HxTrait;
+use App\Service\ApplicantInsuranceCascade;
 use App\Service\BookingConfigurator;
 use App\Service\BookingCreateContextFactory;
 use App\Service\BookingSessionManager;
@@ -34,6 +35,7 @@ class Step2ParticipantController extends AbstractController
         private readonly TravelDataProvider $travelDataService,
         private readonly ParticipantDataPrefiller $prepopulationService,
         private readonly ParticipantFormSupport $participantFormSupportService,
+        private readonly ApplicantInsuranceCascade $applicantInsuranceCascade,
     ) {
     }
 
@@ -70,6 +72,7 @@ class Step2ParticipantController extends AbstractController
             $this->prepopulationService->fillDummyParticipant($bookingDto->participants[$index], $index);
 
             $this->bookingService->preselectDefaultServices($bookingDto);
+            $this->applicantInsuranceCascade->apply($bookingDto);
             $this->bookingService->applyCreateBookingStatusRules($bookingDto);
             $this->bookingSessionService->saveBookingDto($request, $bookingDto, BookingDto::MODE_CREATE);
 
@@ -80,6 +83,7 @@ class Step2ParticipantController extends AbstractController
 
         if (true === $isSubmitted) {
             $this->bookingService->preselectDefaultServices($bookingDto);
+            $this->applicantInsuranceCascade->apply($bookingDto);
             $this->bookingService->applyCreateBookingStatusRules($bookingDto);
         }
 
@@ -195,6 +199,7 @@ class Step2ParticipantController extends AbstractController
         $form->handleRequest($request);
 
         $this->bookingService->preselectDefaultServices($bookingDto);
+        $this->applicantInsuranceCascade->apply($bookingDto);
         if (BookingDto::MODE_CREATE === $bookingDto->getMode()) {
             $this->bookingService->applyCreateBookingStatusRules($bookingDto);
         }
diff --git a/src/Controller/Booking/Edit/ParticipantController.php b/src/Controller/Booking/Edit/ParticipantController.php
index 2336b3b..cba58db 100644
--- a/src/Controller/Booking/Edit/ParticipantController.php
+++ b/src/Controller/Booking/Edit/ParticipantController.php
@@ -10,12 +10,13 @@ use App\Entity\User;
 use App\Form\BookingParticipantType;
 use App\Form\Model\BookingDto;
 use App\Htmx\HxTrait;
+use App\Service\ApplicantInsuranceCascade;
+use App\Service\BookingConfigurator;
 use App\Service\BookingEditContextFactory;
 use App\Service\BookingEditDataLoader;
 use App\Service\BookingEditDraftManager;
-use App\Service\BookingConfigurator;
-use App\Service\ParticipantDataPrefiller;
 use App\Service\BookingSessionManager;
+use App\Service\ParticipantDataPrefiller;
 use App\Service\ParticipantFormSupport;
 use Psr\Log\LoggerInterface;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
@@ -40,6 +41,7 @@ class ParticipantController extends AbstractController
         private readonly BookingSessionManager $bookingSessionService,
         private readonly ParticipantDataPrefiller $prepopulationService,
         private readonly ParticipantFormSupport $participantFormSupportService,
+        private readonly ApplicantInsuranceCascade $applicantInsuranceCascade,
         private readonly LoggerInterface $logger,
     ) {
     }
@@ -85,6 +87,7 @@ class ParticipantController extends AbstractController
         }
 
         $this->editContextFactory->prepareBookingDto($bookingDto);
+        $this->applicantInsuranceCascade->apply($bookingDto);
 
         $form = $this->createParticipantForm($bookingDto, $index);
 
@@ -156,6 +159,7 @@ class ParticipantController extends AbstractController
         $form->handleRequest($request);
 
         $this->bookingConfigurator->preselectDefaultServices($bookingDto);
+        $this->applicantInsuranceCascade->apply($bookingDto);
         $this->bookingSessionService->saveBookingDto($request, $bookingDto, BookingDto::MODE_EDIT);
 
         $form = $this->createForm(
@@ -221,7 +225,6 @@ class ParticipantController extends AbstractController
     }
 
     /**
-     * @param Booking|null $bookingData
      * @param FormInterface<mixed> $form
      */
     private function renderParticipantForm(
@@ -230,8 +233,7 @@ class ParticipantController extends AbstractController
         BookingDto $bookingDto,
         int $bookingId,
         ?Booking $bookingData,
-    ): Response
-    {
+    ): Response {
         $context = $this->editContextFactory->createParticipantContext($bookingDto, $bookingData);
 
         return $this->render('booking/edit/participant.html.twig', [
diff --git a/src/Service/ApplicantInsuranceCascade.php b/src/Service/ApplicantInsuranceCascade.php
new file mode 100644
index 0000000..a24b4c5
--- /dev/null
+++ b/src/Service/ApplicantInsuranceCascade.php
@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+use App\Form\Model\BookingDto;
+
+/**
+ * Propagates the applicant's insurance selection to the other participants.
+ *
+ * This runs during the request cycle rather than only at payload build time, so the
+ * session DTO always reflects the coverage that will actually be booked. Every consumer
+ * that reads ParticipantDto::$insurance - the sidebar summary, the price totals, the
+ * voucher math - is then correct by construction, instead of having to re-derive the
+ * effective insurance for itself.
+ */
+class ApplicantInsuranceCascade
+{
+    public function __construct(
+        private readonly InsuranceManager $insuranceService,
+        private readonly BookingPriceCalculator $priceCalculatorService,
+    ) {
+    }
+
+    /**
+     * Applies the applicant's insurance to other participants if their selection requires it.
+     *
+     * Runs when either:
+     * - Bulk insurance is active (applicant's bulkInsuranceBooking = true): assigns the
+     *   applicant's insurance TYPE to all dependent participants with automatic price tier
+     *   adjustment based on each participant's individual cost.
+     * - The applicant selected a family insurance: family insurance covers the whole family
+     *   under a single policy, so dependents must never hold their own insurance, regardless
+     *   of whether the bulk checkbox was checked.
+     *
+     * IMPORTANT: In edit mode, non-family bulk insurance only applies to participants who:
+     * 1. Currently have NO insurance assigned (insurance === null)
+     * 2. OR whose insurance was already assigned via previous bulk operation
+     *
+     * This prevents overriding individually selected insurances that are locked. Family
+     * insurance is exempt from this protection: dependents can never legitimately hold
+     * their own policy alongside it, so their insurance is always cleared, in edit mode too.
+     *
+     * The assignment is deterministic, so applying it repeatedly across successive requests
+     * converges on the same result.
+     *
+     * @param BookingDto $bookingDto The booking DTO (create or edit flow)
+     */
+    public function apply(BookingDto $bookingDto): void
+    {
+        $applicant = $bookingDto->getParticipant(0);
+
+        if (null === $applicant || null === $applicant->insurance) {
+            return;
+        }
+
+        $isFamilyInsurance = true === $applicant->insurance->familyInsurance;
+
+        // Check if bulk insurance is enabled OR the applicant's selection is a family
+        // insurance (which always applies to dependents, independent of the bulk checkbox)
+        if (false === $applicant->bulkInsuranceBooking && false === $isFamilyInsurance) {
+            return;
+        }
+
+        // Get selectable (non-complementary) insurances with caching
+        $selectableInsurances = $this->insuranceService->getSelectableInsurances($bookingDto->travel);
+
+        // Calculate travel prices for all participants (excluding insurance)
+        $participantPrices = [];
+        foreach ($bookingDto->getParticipants() as $index => $participant) {
+            $participantPrices[$index] = $this->priceCalculatorService->calculateIndividualParticipantPriceExcludingInsurance($bookingDto, $index);
+        }
+
+        // Use InsuranceManager for proper type-based assignment with price tier matching
+        $assignments = $this->insuranceService->batchAssignInsuranceToParticipants(
+            $selectableInsurances,
+            $applicant->insurance,
+            $bookingDto,
+            $participantPrices
+        );
+
+        // Apply assignments to all participants; for non-family insurance skip the applicant
+        // (they already hold the insurance they selected themselves)
+        foreach ($assignments as $index => $insurance) {
+            if (0 === $index && false === $isFamilyInsurance) {
+                continue;
+            }
+
+            $participant = $bookingDto->getParticipant($index);
+            if (null === $participant) {
+                continue;
+            }
+
+            // In edit mode: non-family bulk assignment must not overwrite an individually
+            // locked insurance. Family insurance always overrides, since dependents can
+            // never legitimately keep their own policy alongside it.
+            if (BookingDto::MODE_EDIT === $bookingDto->getMode() && false === $isFamilyInsurance && null !== $participant->insurance) {
+                continue; // Skip participants with existing insurance assignment
+            }
+
+            $participant->insurance = $insurance;
+        }
+    }
+}
diff --git a/src/Service/BookingPricingAssembler.php b/src/Service/BookingPricingAssembler.php
index fa59fc3..2304215 100644
--- a/src/Service/BookingPricingAssembler.php
+++ b/src/Service/BookingPricingAssembler.php
@@ -23,8 +23,6 @@ class BookingPricingAssembler
     public function __construct(
         private readonly RoomPricingCalculator $roomPricingCalculator,
         private readonly ParticipantEligibilityChecker $participantEligibilityChecker,
-        private readonly InsuranceManager $insuranceService,
-        private readonly ParticipantPricingCalculator $participantPricingCalculator,
     ) {
     }
 
@@ -327,7 +325,9 @@ class BookingPricingAssembler
             $this->addToServiceAggregation($serviceAggregation, $participant->rentalInsurance);
         }
 
-        $insuranceToAggregate = $this->resolveInsuranceForAggregation($participant, $bookingDto);
+        // The session DTO is kept truthful by ApplicantInsuranceCascade, which materialises
+        // bulk and family assignments as they are made - so this is simply what the participant holds.
+        $insuranceToAggregate = $participant->insurance;
         if (null !== $insuranceToAggregate && null !== $insuranceToAggregate->price && false === $insuranceToAggregate->isNoInsurance()) {
             $this->addInsuranceToServiceAggregation($serviceAggregation, $insuranceToAggregate);
         }
@@ -404,38 +404,4 @@ class BookingPricingAssembler
             'subType' => $serviceData['subType'] ?? null,
         ];
     }
-
-    private function resolveInsuranceForAggregation(ParticipantDto $participant, BookingDto $bookingDto): ?Insurance
-    {
-        if (null !== $participant->insurance) {
-            return $participant->insurance;
-        }
-
-        $applicant = $bookingDto->getParticipant(0);
-        if (null === $applicant || false === $applicant->bulkInsuranceBooking || null === $applicant->insurance) {
-            return null;
-        }
-
-        if (0 === $participant->index) {
-            return $participant->insurance;
-        }
-
-        $selectableInsurances = $this->insuranceService->getSelectableInsurances($bookingDto->travel);
-        $sameTypeInsurances = $this->insuranceService->filterByType(
-            $selectableInsurances,
-            $applicant->insurance
-        );
-        $travelPrice = $this->participantPricingCalculator->calculateIndividualParticipantPriceExcludingInsurance(
-            $bookingDto,
-            $participant->index
-        );
-        $eligibleInsurances = $this->insuranceService->getEligibleInsurances(
-            $sameTypeInsurances,
-            $participant,
-            $bookingDto,
-            $travelPrice
-        );
-
-        return !empty($eligibleInsurances) ? array_values($eligibleInsurances)[0] : null;
-    }
 }
diff --git a/src/Service/ParticipantPricingCalculator.php b/src/Service/ParticipantPricingCalculator.php
index 387eb6d..1e70cb0 100644
--- a/src/Service/ParticipantPricingCalculator.php
+++ b/src/Service/ParticipantPricingCalculator.php
@@ -4,7 +4,6 @@ declare(strict_types=1);
 
 namespace App\Service;
 
-use App\BusProNet\Model\Insurance;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
 
@@ -54,7 +53,7 @@ class ParticipantPricingCalculator
         }
 
         // Add service prices for this participant (with booking context for bulk insurance)
-        $totalPrice += $this->calculateParticipantServiceTotal($participant, true, $bookingDto);
+        $totalPrice += $this->calculateParticipantServiceTotal($participant, true);
 
         return $totalPrice;
     }
@@ -138,62 +137,24 @@ class ParticipantPricingCalculator
 
             // Add service prices for this participant (excluding insurance)
             // For insurance eligibility calculation, only include services marked with versicherungsberechnung='J'
-            $totalPrice += $this->calculateParticipantServiceTotal($participant, false, null, true);
+            $totalPrice += $this->calculateParticipantServiceTotal($participant, false, true);
 
             return $totalPrice;
         })();
     }
 
-    /**
-     * Gets the effective insurance for a participant, considering bulk insurance assignment.
-     *
-     * When bulk insurance is active and the participant is a dependent (index > 0),
-     * returns the applicant's insurance. Otherwise returns the participant's own insurance.
-     *
-     * This method is used for pricing calculations to show correct prices when bulk
-     * insurance is enabled, even though the actual assignment happens in the processor.
-     *
-     * @param ParticipantDto  $participant The participant to get insurance for
-     * @param BookingDto|null $bookingDto  Optional booking DTO for bulk insurance check
-     *
-     * @return Insurance|null The effective insurance for pricing purposes
-     */
-    public function getEffectiveInsurance(ParticipantDto $participant, ?BookingDto $bookingDto): ?Insurance
-    {
-        // If no booking context, use participant's own insurance
-        if (null === $bookingDto) {
-            return $participant->insurance;
-        }
-
-        // Applicant always uses their own insurance
-        if (0 === $participant->index) {
-            return $participant->insurance;
-        }
-
-        // Check if bulk insurance is active
-        $applicant = $bookingDto->getParticipant(0);
-        if (null === $applicant || false === $applicant->bulkInsuranceBooking) {
-            return $participant->insurance;
-        }
-
-        // Bulk insurance is active - use applicant's insurance for dependent participants
-        return $applicant->insurance;
-    }
-
     /**
      * Calculates the total service cost for a single participant.
      *
-     * @param ParticipantDto  $participant                      The participant to calculate services for
-     * @param bool            $includeInsurance                 Whether to include insurance pricing (default: true)
-     * @param BookingDto|null $bookingDto                       Optional booking DTO for bulk insurance resolution
-     * @param bool            $onlyInsuranceCalculationServices Only include services with includeInInsuranceCalculation=true (default: false)
+     * @param ParticipantDto $participant                      The participant to calculate services for
+     * @param bool           $includeInsurance                 Whether to include insurance pricing (default: true)
+     * @param bool           $onlyInsuranceCalculationServices Only include services with includeInInsuranceCalculation=true (default: false)
      *
      * @return float The total service cost for this participant
      */
     public function calculateParticipantServiceTotal(
         ParticipantDto $participant,
         bool $includeInsurance = true,
-        ?BookingDto $bookingDto = null,
         bool $onlyInsuranceCalculationServices = false,
     ): float {
         $serviceTotal = 0.0;
@@ -212,7 +173,9 @@ class ParticipantPricingCalculator
         }
 
         // Get effective insurance (considering bulk insurance for dependent participants)
-        $effectiveInsurance = $this->getEffectiveInsurance($participant, $bookingDto);
+        // ApplicantInsuranceCascade materialises bulk and family assignments into the DTO as
+        // they happen, so the participant's own field is already the effective insurance.
+        $effectiveInsurance = $participant->insurance;
         if ($includeInsurance && null !== $effectiveInsurance && null !== $effectiveInsurance->price) {
             $serviceTotal += $effectiveInsurance->price;
         }
diff --git a/tests/BusProNet/DataProcessor/BookingDataProcessorTest.php b/tests/BusProNet/DataProcessor/BookingDataProcessorTest.php
index b2f14b7..03d6c36 100644
--- a/tests/BusProNet/DataProcessor/BookingDataProcessorTest.php
+++ b/tests/BusProNet/DataProcessor/BookingDataProcessorTest.php
@@ -21,6 +21,7 @@ use App\BusProNet\Model\Service;
 use App\BusProNet\Model\Travel;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
+use App\Service\ApplicantInsuranceCascade;
 use App\Service\BookingPriceCalculator;
 use App\Service\InsuranceManager;
 use PHPUnit\Framework\TestCase;
@@ -63,6 +64,7 @@ class BookingDataProcessorTest extends TestCase
             $serviceProcessor,
             $payloadBuilder,
             $personalDataSynchronizer,
+            new ApplicantInsuranceCascade($insuranceService, $priceCalculatorService),
         );
     }
 
@@ -876,6 +878,7 @@ class BookingDataProcessorTest extends TestCase
             new ParticipantServiceProcessor(new NullLogger()),
             $payloadBuilder,
             new PersonalDataSynchronizer(),
+            new ApplicantInsuranceCascade($insuranceService, $priceCalculatorService),
         );
 
         $processor->createBookingRequestPayload($bookingDto, 'ANFRAGE');
@@ -925,6 +928,7 @@ class BookingDataProcessorTest extends TestCase
             new ParticipantServiceProcessor(new NullLogger()),
             new BookingPayloadBuilder(new ServiceMappingCollector()),
             new PersonalDataSynchronizer(),
+            new ApplicantInsuranceCascade($insuranceService, $priceCalculatorService),
         );
 
         $processor->createUpdateRequestPayload($formData);
@@ -978,6 +982,7 @@ class BookingDataProcessorTest extends TestCase
             new ParticipantServiceProcessor(new NullLogger()),
             $payloadBuilder,
             new PersonalDataSynchronizer(),
+            new ApplicantInsuranceCascade($insuranceService, $priceCalculatorService),
         );
 
         $processor->createBookingRequestPayload($bookingDto, 'ANFRAGE');
@@ -1024,6 +1029,7 @@ class BookingDataProcessorTest extends TestCase
             new ParticipantServiceProcessor(new NullLogger()),
             $payloadBuilder,
             new PersonalDataSynchronizer(),
+            new ApplicantInsuranceCascade($insuranceService, $priceCalculatorService),
         );
 
         $processor->createBookingRequestPayload($bookingDto, 'ANFRAGE');
@@ -1069,6 +1075,7 @@ class BookingDataProcessorTest extends TestCase
             new ParticipantServiceProcessor(new NullLogger()),
             $payloadBuilder,
             new PersonalDataSynchronizer(),
+            new ApplicantInsuranceCascade($insuranceService, $priceCalculatorService),
         );
 
         $processor->createBookingRequestPayload($bookingDto, 'ANFRAGE');
diff --git a/tests/Controller/Booking/Edit/ParticipantControllerTest.php b/tests/Controller/Booking/Edit/ParticipantControllerTest.php
index eb64cd0..6b4a70d 100644
--- a/tests/Controller/Booking/Edit/ParticipantControllerTest.php
+++ b/tests/Controller/Booking/Edit/ParticipantControllerTest.php
@@ -4,9 +4,9 @@ declare(strict_types=1);
 
 namespace App\Tests\Controller\Booking\Edit;
 
+use App\BusProNet\ApiClient;
 use App\BusProNet\Model\Booking;
 use App\BusProNet\Model\Travel;
-use App\BusProNet\ApiClient;
 use App\Controller\Booking\Edit\ParticipantController;
 use App\Entity\User;
 use App\Form\BookingParticipantType;
@@ -15,6 +15,8 @@ use App\Form\Model\BookingEditContext;
 use App\Form\Model\BookingSummaryDto;
 use App\Form\Model\ParticipantDto;
 use App\Form\Model\ParticipantEditDto;
+use App\Security\Crypt;
+use App\Service\ApplicantInsuranceCascade;
 use App\Service\BookingConfigurator;
 use App\Service\BookingEditContextFactory;
 use App\Service\BookingEditDataLoader;
@@ -22,7 +24,6 @@ use App\Service\BookingEditDraftManager;
 use App\Service\BookingSessionManager;
 use App\Service\ParticipantDataPrefiller;
 use App\Service\ParticipantFormSupport;
-use App\Security\Crypt;
 use Carbon\CarbonImmutable;
 use PHPUnit\Framework\TestCase;
 use Psr\Log\LoggerInterface;
@@ -133,6 +134,7 @@ class ParticipantControllerTest extends TestCase
             $bookingSessionService,
             $prepopulationService,
             $participantFormSupportService,
+            $this->createMock(ApplicantInsuranceCascade::class),
             $user,
             $form,
         );
@@ -241,6 +243,7 @@ class ParticipantControllerTest extends TestCase
             $bookingSessionService,
             $prepopulationService,
             $participantFormSupportService,
+            $this->createMock(ApplicantInsuranceCascade::class),
             $user,
             $form,
         );
@@ -317,6 +320,7 @@ final class TestableParticipantController extends ParticipantController
         BookingSessionManager $bookingSessionService,
         ParticipantDataPrefiller $prepopulationService,
         ParticipantFormSupport $participantFormSupportService,
+        ApplicantInsuranceCascade $applicantInsuranceCascade,
         private readonly User $user,
         FormInterface $form,
     ) {
@@ -330,6 +334,7 @@ final class TestableParticipantController extends ParticipantController
             $bookingSessionService,
             $prepopulationService,
             $participantFormSupportService,
+            $applicantInsuranceCascade,
             new NullLogger(),
         );
     }
diff --git a/tests/Service/ApplicantInsuranceCascadeTest.php b/tests/Service/ApplicantInsuranceCascadeTest.php
new file mode 100644
index 0000000..54ee81b
--- /dev/null
+++ b/tests/Service/ApplicantInsuranceCascadeTest.php
@@ -0,0 +1,250 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Service;
+
+use App\BusProNet\Model\Booking;
+use App\BusProNet\Model\Insurance;
+use App\BusProNet\Model\Travel;
+use App\Form\Model\BookingDto;
+use App\Form\Model\ParticipantDto;
+use App\Service\ApplicantInsuranceCascade;
+use App\Service\BookingPriceCalculator;
+use App\Service\InsuranceManager;
+use PHPUnit\Framework\TestCase;
+
+class ApplicantInsuranceCascadeTest extends TestCase
+{
+    /**
+     * Regression for the production report: an adult and two children each picked their own
+     * insurance, then the applicant switched to the family insurance that had become available.
+     * The dependents' own selections used to survive in the session DTO until submit, which is
+     * what left the sidebar summary listing two superseded policies.
+     */
+    public function testFamilyInsuranceClearsDependentsOwnSelections(): void
+    {
+        $familyInsurance = $this->createInsurance('family-1', true);
+        $childInsuranceA = $this->createInsurance('child-a', false);
+        $childInsuranceB = $this->createInsurance('child-b', false);
+
+        $bookingDto = $this->createBooking([
+            $this->createParticipant(0, $familyInsurance),
+            $this->createParticipant(1, $childInsuranceA),
+            $this->createParticipant(2, $childInsuranceB),
+        ]);
+
+        $cascade = $this->createCascade([
+            0 => $familyInsurance,
+            1 => null,
+            2 => null,
+        ], [$familyInsurance, $childInsuranceA, $childInsuranceB]);
+
+        $cascade->apply($bookingDto);
+
+        $this->assertSame($familyInsurance, $bookingDto->participants[0]->insurance);
+        $this->assertNull($bookingDto->participants[1]->insurance, 'First child must lose their own policy');
+        $this->assertNull($bookingDto->participants[2]->insurance, 'Second child must lose their own policy');
+    }
+
+    /**
+     * The cascade runs on every request, so applying it repeatedly must converge rather than
+     * drift - otherwise a simple page refresh could change the booking.
+     */
+    public function testApplyingTwiceIsIdempotent(): void
+    {
+        $familyInsurance = $this->createInsurance('family-1', true);
+        $childInsurance = $this->createInsurance('child-a', false);
+
+        $bookingDto = $this->createBooking([
+            $this->createParticipant(0, $familyInsurance),
+            $this->createParticipant(1, $childInsurance),
+        ]);
+
+        $cascade = $this->createCascade([
+            0 => $familyInsurance,
+            1 => null,
+        ], [$familyInsurance, $childInsurance]);
+
+        $cascade->apply($bookingDto);
+        $cascade->apply($bookingDto);
+
+        $this->assertSame($familyInsurance, $bookingDto->participants[0]->insurance);
+        $this->assertNull($bookingDto->participants[1]->insurance);
+    }
+
+    /**
+     * Family insurance propagates on its own merit - the bulk checkbox is irrelevant to it.
+     */
+    public function testFamilyInsurancePropagatesWithoutBulkCheckbox(): void
+    {
+        $familyInsurance = $this->createInsurance('family-1', true);
+        $childInsurance = $this->createInsurance('child-a', false);
+
+        $applicant = $this->createParticipant(0, $familyInsurance);
+        $applicant->bulkInsuranceBooking = false;
+
+        $bookingDto = $this->createBooking([$applicant, $this->createParticipant(1, $childInsurance)]);
+
+        $cascade = $this->createCascade([0 => $familyInsurance, 1 => null], [$familyInsurance, $childInsurance]);
+        $cascade->apply($bookingDto);
+
+        $this->assertNull($bookingDto->participants[1]->insurance);
+    }
+
+    /**
+     * Bulk booking assigns the applicant's insurance type to dependents, re-tiered per
+     * participant by InsuranceManager.
+     */
+    public function testBulkInsuranceAssignsTierToDependents(): void
+    {
+        $applicantInsurance = $this->createInsurance('tier-high', false);
+        $dependentTier = $this->createInsurance('tier-low', false);
+
+        $applicant = $this->createParticipant(0, $applicantInsurance);
+        $applicant->bulkInsuranceBooking = true;
+
+        $dependent = $this->createParticipant(1, null);
+
+        $bookingDto = $this->createBooking([$applicant, $dependent]);
+
+        $cascade = $this->createCascade([
+            0 => $applicantInsurance,
+            1 => $dependentTier,
+        ], [$applicantInsurance, $dependentTier]);
+
+        $cascade->apply($bookingDto);
+
+        $this->assertSame($applicantInsurance, $bookingDto->participants[0]->insurance, 'Applicant keeps their own choice');
+        $this->assertSame($dependentTier, $bookingDto->participants[1]->insurance);
+    }
+
+    /**
+     * Neither bulk nor family: every participant keeps whatever they chose individually.
+     */
+    public function testNoPropagationWithoutBulkOrFamily(): void
+    {
+        $applicantInsurance = $this->createInsurance('own-a', false);
+        $dependentInsurance = $this->createInsurance('own-b', false);
+
+        $bookingDto = $this->createBooking([
+            $this->createParticipant(0, $applicantInsurance),
+            $this->createParticipant(1, $dependentInsurance),
+        ]);
+
+        $insuranceService = $this->createMock(InsuranceManager::class);
+        $insuranceService->expects($this->never())->method('batchAssignInsuranceToParticipants');
+
+        $cascade = new ApplicantInsuranceCascade(
+            $insuranceService,
+            $this->createMock(BookingPriceCalculator::class)
+        );
+
+        $cascade->apply($bookingDto);
+
+        $this->assertSame($applicantInsurance, $bookingDto->participants[0]->insurance);
+        $this->assertSame($dependentInsurance, $bookingDto->participants[1]->insurance);
+    }
+
+    /**
+     * In edit mode a dependent's individually selected, locked-in insurance must survive a
+     * non-family bulk assignment.
+     */
+    public function testEditModeKeepsIndividuallySelectedInsuranceForNonFamilyBulk(): void
+    {
+        $applicantInsurance = $this->createInsurance('tier-high', false);
+        $dependentOwn = $this->createInsurance('dependent-own', false);
+        $wouldBeAssigned = $this->createInsurance('tier-low', false);
+
+        $applicant = $this->createParticipant(0, $applicantInsurance);
+        $applicant->bulkInsuranceBooking = true;
+
+        $bookingDto = $this->createBooking([$applicant, $this->createParticipant(1, $dependentOwn)]);
+        $bookingDto->booking = new Booking(); // BookingDto derives MODE_EDIT from a present booking
+
+        $cascade = $this->createCascade([
+            0 => $applicantInsurance,
+            1 => $wouldBeAssigned,
+        ], [$applicantInsurance, $dependentOwn, $wouldBeAssigned]);
+
+        $cascade->apply($bookingDto);
+
+        $this->assertSame($dependentOwn, $bookingDto->participants[1]->insurance, 'Locked individual selection must survive');
+    }
+
+    /**
+     * Family insurance is exempt from the edit-mode protection: a dependent can never
+     * legitimately hold their own policy alongside it.
+     */
+    public function testEditModeFamilyInsuranceStillClearsDependents(): void
+    {
+        $familyInsurance = $this->createInsurance('family-1', true);
+        $dependentOwn = $this->createInsurance('dependent-own', false);
+
+        $bookingDto = $this->createBooking([
+            $this->createParticipant(0, $familyInsurance),
+            $this->createParticipant(1, $dependentOwn),
+        ]);
+        $bookingDto->booking = new Booking(); // BookingDto derives MODE_EDIT from a present booking
+
+        $cascade = $this->createCascade([0 => $familyInsurance, 1 => null], [$familyInsurance, $dependentOwn]);
+        $cascade->apply($bookingDto);
+
+        $this->assertNull($bookingDto->participants[1]->insurance);
+    }
+
+    // Helpers
+
+    /**
+     * @param array<int, Insurance|null> $assignments
+     * @param array<Insurance>           $selectable
+     */
+    private function createCascade(array $assignments, array $selectable): ApplicantInsuranceCascade
+    {
+        $insuranceService = $this->createMock(InsuranceManager::class);
+        $insuranceService->method('getSelectableInsurances')->willReturn($selectable);
+        $insuranceService->method('batchAssignInsuranceToParticipants')->willReturn($assignments);
+
+        $priceCalculator = $this->createMock(BookingPriceCalculator::class);
+        $priceCalculator->method('calculateIndividualParticipantPriceExcludingInsurance')->willReturn(0.0);
+
+        return new ApplicantInsuranceCascade($insuranceService, $priceCalculator);
+    }
+
+    private function createInsurance(string $id, bool $familyInsurance): Insurance
+    {
+        $insurance = new Insurance();
+        $insurance->id = $id;
+        $insurance->label = 'Insurance '.$id;
+        $insurance->price = 50.0;
+        $insurance->subType = 'RRV';
+        $insurance->package = false;
+        $insurance->complementary = false;
+        $insurance->familyInsurance = $familyInsurance;
+
+        return $insurance;
+    }
+
+    private function createParticipant(int $index, ?Insurance $insurance): ParticipantDto
+    {
+        $participant = new ParticipantDto();
+        $participant->index = $index;
+        $participant->insurance = $insurance;
+
+        return $participant;
+    }
+
+    /** @param array<ParticipantDto> $participants */
+    private function createBooking(array $participants): BookingDto
+    {
+        $travel = new Travel();
+        $travel->id = 1;
+        $travel->dateFrom = new \DateTimeImmutable('2026-02-01');
+        $travel->dateTo = new \DateTimeImmutable('2026-02-08');
+
+        $bookingDto = new BookingDto($travel, count($participants));
+        $bookingDto->participants = $participants;
+
+        return $bookingDto;
+    }
+}
diff --git a/tests/Service/BookingPriceCalculatorTest.php b/tests/Service/BookingPriceCalculatorTest.php
index e4c75ac..5e97afd 100644
--- a/tests/Service/BookingPriceCalculatorTest.php
+++ b/tests/Service/BookingPriceCalculatorTest.php
@@ -36,8 +36,6 @@ class BookingPriceCalculatorTest extends TestCase
         $this->pricingAssembler = new BookingPricingAssembler(
             $this->roomPricingCalculator,
             $eligibilityChecker,
-            new InsuranceManager(),
-            $this->participantPricingCalculator,
         );
 
         $this->service = new BookingPriceCalculator(
diff --git a/tests/Service/BookingPricingAssemblerTest.php b/tests/Service/BookingPricingAssemblerTest.php
index ba22dcd..a96cd69 100644
--- a/tests/Service/BookingPricingAssemblerTest.php
+++ b/tests/Service/BookingPricingAssemblerTest.php
@@ -8,6 +8,8 @@ use App\BusProNet\Model\Insurance;
 use App\BusProNet\Model\Travel;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
+use App\Service\ApplicantInsuranceCascade;
+use App\Service\BookingPriceCalculator;
 use App\Service\BookingPricingAssembler;
 use App\Service\InsuranceManager;
 use App\Service\ParticipantEligibilityChecker;
@@ -83,6 +85,10 @@ class BookingPricingAssemblerTest extends TestCase
         $bookingDto = new BookingDto($travel, 3);
         $bookingDto->participants = [$participant1, $participant2, $participant3];
 
+        // Bulk assignment is materialised into the DTO by the cascade; the assembler then
+        // simply reports what each participant holds.
+        $this->createCascade()->apply($bookingDto);
+
         $result = $this->assembler->calculateServicePricing($bookingDto);
 
         // 3× same insurance should aggregate into one line item
@@ -207,6 +213,8 @@ class BookingPricingAssemblerTest extends TestCase
         $bookingDto = new BookingDto($travel, 3);
         $bookingDto->participants = [$participant1, $participant2, $participant3];
 
+        $this->createCascade()->apply($bookingDto);
+
         $result = $this->assembler->calculateServicePricing($bookingDto);
 
         $insuranceGroup = $this->findServiceGroup($result, 'Reiseversicherungen');
@@ -216,8 +224,93 @@ class BookingPricingAssemblerTest extends TestCase
         $this->assertEquals(3, $totalParticipants, 'Should count all 3 participants across all tiers');
     }
 
+    /**
+     * Regression for the production report: an adult and two children each picked their own
+     * insurance, then the applicant switched to the family insurance that had become
+     * available. The sidebar kept listing the two children's superseded policies, and the
+     * grand total stayed inflated by their premiums.
+     *
+     * The sidebar reports whatever the DTO holds, so this asserts the end-to-end contract:
+     * once ApplicantInsuranceCascade has run, only the family policy remains to aggregate.
+     */
+    public function testFamilyInsuranceLeavesOnlyOneInsuranceLineItem(): void
+    {
+        $travel = $this->createFamilyTravel();
+
+        $familyInsurance = $this->createInsurance(1, 'Familienversicherung', 120.0);
+        $familyInsurance->familyInsurance = true;
+
+        $applicant = $this->createParticipantWithAge(0, '1985-06-15');
+        $applicant->insurance = $familyInsurance;
+        $applicant->bulkInsuranceBooking = false;
+
+        $childOne = $this->createParticipantWithAge(1, '2016-01-01');
+        $childOne->insurance = $this->createInsurance(2, 'Insurance A', 50.0);
+
+        $childTwo = $this->createParticipantWithAge(2, '2018-01-01');
+        $childTwo->insurance = $this->createInsurance(3, 'Insurance B', 75.0);
+
+        $travel->insurances = [$familyInsurance];
+
+        $bookingDto = new BookingDto($travel, 3);
+        $bookingDto->participants = [$applicant, $childOne, $childTwo];
+
+        $this->createCascade()->apply($bookingDto);
+
+        $result = $this->assembler->calculateServicePricing($bookingDto);
+
+        $insuranceGroup = $this->findServiceGroup($result, 'Reiseversicherungen');
+        $this->assertNotNull($insuranceGroup, 'Insurance group should exist');
+        $this->assertCount(
+            1,
+            $insuranceGroup['services'],
+            'Only the family policy may be listed - the children\'s superseded selections must be gone'
+        );
+
+        $lineItem = array_values($insuranceGroup['services'])[0];
+        $this->assertSame('Familienversicherung', $lineItem['label']);
+        $this->assertEquals(1, $lineItem['participantCount'], 'Family policy is held once, by the applicant');
+        $this->assertEqualsWithDelta(120.0, $insuranceGroup['groupTotal'], 0.001, 'Total must not include the children\'s former premiums');
+    }
+
     // Helpers
 
+    private function createCascade(): ApplicantInsuranceCascade
+    {
+        $roomPricingCalculator = new RoomPricingCalculator();
+        $participantPricingCalculator = new ParticipantPricingCalculator($roomPricingCalculator);
+        $insuranceManager = new InsuranceManager();
+
+        return new ApplicantInsuranceCascade(
+            $insuranceManager,
+            new BookingPriceCalculator(
+                $roomPricingCalculator,
+                $this->createAssembler($this->eligibilityChecker),
+                $participantPricingCalculator
+            )
+        );
+    }
+
+    private function createFamilyTravel(): Travel
+    {
+        $travel = new Travel();
+        $travel->id = 1;
+        $travel->dateFrom = new \DateTimeImmutable('2026-02-01');
+        $travel->dateTo = new \DateTimeImmutable('2026-02-08');
+        $travel->insurances = [];
+
+        return $travel;
+    }
+
+    private function createParticipantWithAge(int $index, string $dateOfBirth): ParticipantDto
+    {
+        $participant = new ParticipantDto();
+        $participant->index = $index;
+        $participant->dateOfBirth = new \DateTimeImmutable($dateOfBirth);
+
+        return $participant;
+    }
+
     private function createAssembler(ParticipantEligibilityChecker $eligibilityChecker): BookingPricingAssembler
     {
         $roomPricingCalculator = new RoomPricingCalculator();
@@ -225,8 +318,6 @@ class BookingPricingAssemblerTest extends TestCase
         return new BookingPricingAssembler(
             $roomPricingCalculator,
             $eligibilityChecker,
-            new InsuranceManager(),
-            new ParticipantPricingCalculator($roomPricingCalculator),
         );
     }