diff --git a/src/EventListener/InvalidateApplicationsListener.php b/src/EventListener/InvalidateApplicationsListener.php
new file mode 100644
index 0000000..b7aac3d
--- /dev/null
+++ b/src/EventListener/InvalidateApplicationsListener.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace App\EventListener;
+
+use App\Entity\Application;
+use App\Entity\Upload;
+use App\Event\DocumentConfirmedEvent;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\EventDispatcher\Attribute\AsEventListener;
+
+#[AsEventListener(event: DocumentConfirmedEvent::NAME, method: 'onDocumentConfirmed')]
+class InvalidateApplicationsListener
+{
+    public function __construct(
+        private readonly EntityManagerInterface $entityManager,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    public function onDocumentConfirmed(DocumentConfirmedEvent $event): void
+    {
+        $document = $event->getDocument();
+
+        if (Upload::TYPE_CONTRACT !== $document->getType()) {
+            return;
+        }
+
+        $disposition = $document->getDisposition();
+        $assignment = $disposition->getAssignment();
+        $teamer = $disposition->getTeamer();
+        $period = $assignment->getEffectivePeriod();
+
+        // Find other applications by this teamer with overlapping date ranges
+        // Two periods overlap when: (start1 < end2) AND (end1 > start2)
+        // This catches all overlap scenarios while excluding boundary-only touching:
+        // - Partial overlaps from either direction
+        // - Complete containment in either direction
+        // - Exact date matches
+        // Note: Periods that only touch at boundaries (e.g., Jan 1-7 and Jan 7-12) are NOT considered overlapping
+        $qb = $this
+            ->entityManager
+            ->getRepository(Application::class)
+            ->createQueryBuilder('application');
+
+        /** @var array<Application> $applications */
+        $applications = $qb
+            ->innerJoin('application.assignment', 'assignment')
+            ->where($qb->expr()->andX(
+                $qb->expr()->eq('application.teamer', ':teamer'),
+                $qb->expr()->lt('assignment.dateFrom', ':dateTo'),
+                $qb->expr()->gt('assignment.dateTo', ':dateFrom'),
+                $qb->expr()->neq('application.status', ':status')
+            ))
+            ->setParameter('teamer', $teamer)
+            ->setParameter('dateFrom', $period->start->toDateTimeImmutable())
+            ->setParameter('dateTo', $period->end->toDateTimeImmutable())
+            ->setParameter('status', Application::STATUS_REJECTED)
+            ->getQuery()
+            ->getResult()
+        ;
+
+        if (0 === count($applications)) {
+            return;
+        }
+
+        foreach ($applications as $application) {
+            $destination = $application->getAssignment()->getDestination();
+            $this->logger->info('Deleted overlapping application', [
+                'teamer' => $teamer,
+                'destination' => $destination->getHotelCode(),
+                'date_from' => $destination->getDateFrom()->format('Y-m-d'),
+                'date_to' => $destination->getDateTo()->format('Y-m-d'),
+            ]);
+            $this->entityManager->remove($application);
+        }
+
+        $this->entityManager->flush();
+    }
+}
diff --git a/tests/EventListener/InvalidateApplicationsListenerTest.php b/tests/EventListener/InvalidateApplicationsListenerTest.php
new file mode 100644
index 0000000..80941e4
--- /dev/null
+++ b/tests/EventListener/InvalidateApplicationsListenerTest.php
@@ -0,0 +1,332 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\EventListener;
+
+use App\Entity\Application;
+use App\Entity\Assignment;
+use App\Entity\Destination;
+use App\Entity\Disposition;
+use App\Entity\Teamer;
+use App\Entity\Upload;
+use App\Event\DocumentConfirmedEvent;
+use App\EventListener\InvalidateApplicationsListener;
+use App\Repository\ApplicationRepository;
+use Carbon\CarbonPeriod;
+use Doctrine\ORM\AbstractQuery;
+use Doctrine\ORM\EntityManagerInterface;
+use Doctrine\ORM\Query\Expr;
+use Doctrine\ORM\QueryBuilder;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+class InvalidateApplicationsListenerTest extends TestCase
+{
+    private EntityManagerInterface&MockObject $entityManager;
+    private InvalidateApplicationsListener $listener;
+    private array $removedApplications = [];
+
+    protected function setUp(): void
+    {
+        $this->entityManager = $this->createMock(EntityManagerInterface::class);
+        $logger = $this->createMock(LoggerInterface::class);
+        $this->removedApplications = [];
+
+        $this->entityManager
+            ->method('remove')
+            ->willReturnCallback(function (Application $application): void {
+                $this->removedApplications[] = $application;
+            });
+
+        $this->listener = new InvalidateApplicationsListener(
+            $this->entityManager,
+            $logger
+        );
+    }
+
+    public function testDoesNotInvalidateApplicationsForNonContractDocuments(): void
+    {
+        $document = $this->createMockUpload(Upload::TYPE_INVOICE);
+
+        $this->entityManager
+            ->expects($this->never())
+            ->method('getRepository');
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testInvalidatesApplicationCompletelyWithinConfirmedPeriod(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+        $overlappingApplication = $this->createMockApplication('2025-01-12', '2025-01-18');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$overlappingApplication]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(1, $this->removedApplications);
+        $this->assertSame($overlappingApplication, $this->removedApplications[0]);
+    }
+
+    public function testInvalidatesApplicationStartingBeforeAndOverlapping(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+        $overlappingApplication = $this->createMockApplication('2025-01-05', '2025-01-15');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$overlappingApplication]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(1, $this->removedApplications);
+    }
+
+    public function testInvalidatesApplicationEndingAfterAndOverlapping(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+        $overlappingApplication = $this->createMockApplication('2025-01-15', '2025-01-25');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$overlappingApplication]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(1, $this->removedApplications);
+    }
+
+    public function testInvalidatesApplicationSpanningEntireConfirmedPeriod(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+        $spanningApplication = $this->createMockApplication('2025-01-05', '2025-01-25');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$spanningApplication]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(1, $this->removedApplications);
+    }
+
+    public function testInvalidatesApplicationWithExactSameDates(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+        $sameApplication = $this->createMockApplication('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$sameApplication]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(1, $this->removedApplications);
+    }
+
+    public function testDoesNotInvalidateApplicationEndingBeforeConfirmedPeriod(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, []);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testDoesNotInvalidateApplicationStartingAfterConfirmedPeriod(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, []);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testInvalidatesMultipleOverlappingApplications(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $application1 = $this->createMockApplication('2025-01-12', '2025-01-14');
+        $application2 = $this->createMockApplication('2025-01-15', '2025-01-18');
+        $application3 = $this->createMockApplication('2025-01-08', '2025-01-25');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$application1, $application2, $application3]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(3, $this->removedApplications);
+    }
+
+    public function testDoesNotInvalidateApplicationTouchingOnBoundary(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, []);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testDoesNotInvalidateRejectedApplications(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, []);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testDoesNotInvalidateApplicationEndingOnSameDayAsConfirmedStart(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, []);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testDoesNotInvalidateApplicationStartingOnSameDayAsConfirmedEnd(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, []);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(0, $this->removedApplications);
+    }
+
+    public function testInvalidatesApplicationWithOneDayActualOverlap(): void
+    {
+        $teamer = $this->createMock(Teamer::class);
+        $confirmedPeriod = new CarbonPeriod('2025-01-10', '2025-01-20');
+        $overlappingApplication = $this->createMockApplication('2025-01-05', '2025-01-11');
+
+        $document = $this->createMockContractWithPeriod($confirmedPeriod, $teamer);
+        $this->setupQueryMock($teamer, $confirmedPeriod, [$overlappingApplication]);
+
+        $event = new DocumentConfirmedEvent($document);
+        $this->listener->onDocumentConfirmed($event);
+
+        $this->assertCount(1, $this->removedApplications);
+    }
+
+    private function createMockUpload(string $type): Upload&MockObject
+    {
+        $upload = $this->createMock(Upload::class);
+        $upload->method('getType')->willReturn($type);
+
+        return $upload;
+    }
+
+    private function createMockContractWithPeriod(CarbonPeriod $period, Teamer $teamer): Upload&MockObject
+    {
+        $destination = $this->createMock(Destination::class);
+        $destination->method('getHotelCode')->willReturn('TST');
+        $destination->method('getDateFrom')->willReturn($period->start->toDateTimeImmutable());
+        $destination->method('getDateTo')->willReturn($period->end->toDateTimeImmutable());
+
+        $assignment = $this->createMock(Assignment::class);
+        $assignment->method('getEffectivePeriod')->willReturn($period);
+        $assignment->method('getDestination')->willReturn($destination);
+
+        $disposition = $this->createMock(Disposition::class);
+        $disposition->method('getAssignment')->willReturn($assignment);
+        $disposition->method('getTeamer')->willReturn($teamer);
+
+        $upload = $this->createMock(Upload::class);
+        $upload->method('getType')->willReturn(Upload::TYPE_CONTRACT);
+        $upload->method('getDisposition')->willReturn($disposition);
+
+        return $upload;
+    }
+
+    private function createMockApplication(string $dateFrom, string $dateTo): Application&MockObject
+    {
+        $destination = $this->createMock(Destination::class);
+        $destination->method('getHotelCode')->willReturn('TST');
+        $destination->method('getDateFrom')->willReturn(new \DateTimeImmutable($dateFrom));
+        $destination->method('getDateTo')->willReturn(new \DateTimeImmutable($dateTo));
+
+        $assignment = $this->createMock(Assignment::class);
+        $assignment->method('getDestination')->willReturn($destination);
+
+        $application = $this->createMock(Application::class);
+        $application->method('getAssignment')->willReturn($assignment);
+
+        return $application;
+    }
+
+    private function setupQueryMock(Teamer $teamer, CarbonPeriod $period, array $applications): void
+    {
+        $query = $this->createMock(AbstractQuery::class);
+        $query->method('getResult')->willReturn($applications);
+
+        $expr = $this->createMock(Expr::class);
+        $expr->method('andX')->willReturnSelf();
+        $expr->method('eq')->willReturnSelf();
+        $expr->method('lte')->willReturnSelf();
+        $expr->method('gte')->willReturnSelf();
+        $expr->method('neq')->willReturnSelf();
+
+        $queryBuilder = $this->createMock(QueryBuilder::class);
+        $queryBuilder->method('expr')->willReturn($expr);
+        $queryBuilder->method('innerJoin')->willReturnSelf();
+        $queryBuilder->method('where')->willReturnSelf();
+        $queryBuilder->method('setParameter')->willReturnSelf();
+        $queryBuilder->method('getQuery')->willReturn($query);
+
+        $repository = $this->createMock(ApplicationRepository::class);
+        $repository
+            ->method('createQueryBuilder')
+            ->with('application')
+            ->willReturn($queryBuilder);
+
+        $this->entityManager
+            ->method('getRepository')
+            ->with(Application::class)
+            ->willReturn($repository);
+    }
+}