diff --git a/src/State/ClientTicketNumberProcessor.php b/src/State/ClientTicketNumberProcessor.php
new file mode 100644
index 0000000..2f1cae1
--- /dev/null
+++ b/src/State/ClientTicketNumberProcessor.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\State;
+
+use ApiPlatform\Metadata\Operation;
+use ApiPlatform\State\ProcessorInterface;
+use App\Entity\ClientTicket;
+use App\Entity\User;
+use App\Repository\ClientTicketRepository;
+use DateTimeImmutable;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+
+/**
+ * @implements ProcessorInterface<ClientTicket, ClientTicket>
+ */
+final readonly class ClientTicketNumberProcessor implements ProcessorInterface
+{
+    public function __construct(
+        private EntityManagerInterface $entityManager,
+        private Security $security,
+        private ClientTicketRepository $clientTicketRepository,
+    ) {}
+
+    public function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = []): ClientTicket
+    {
+        assert($data instanceof ClientTicket);
+
+        $user = $this->security->getUser();
+        assert($user instanceof User);
+
+        if (null === $user->getClient()) {
+            throw new AccessDeniedHttpException('Only client users can create tickets.');
+        }
+
+        $project = $data->getProject();
+        if (null === $project) {
+            throw new BadRequestHttpException('Project is required.');
+        }
+
+        if (!$user->getAllowedProjects()->contains($project)) {
+            throw new AccessDeniedHttpException('You do not have access to this project.');
+        }
+
+        $nextNumber = $this->clientTicketRepository->findNextNumberForProject($project);
+        $data->setNumber($nextNumber);
+        $data->setSubmittedBy($user);
+        $data->setStatus('new');
+        $data->setCreatedAt(new DateTimeImmutable());
+        $data->setUpdatedAt(new DateTimeImmutable());
+
+        $this->entityManager->persist($data);
+        $this->entityManager->flush();
+
+        return $data;
+    }
+}