diff --git a/src/Handler/Customer/RegisterCustomerHandler.php b/src/Handler/Customer/RegisterCustomerHandler.php
index c2a9d1463..22323e498 100644
--- a/src/Handler/Customer/RegisterCustomerHandler.php
+++ b/src/Handler/Customer/RegisterCustomerHandler.php
@@ -5,12 +5,12 @@
 namespace Sylius\ShopApiPlugin\Handler\Customer;
 
 use Sylius\Component\Channel\Repository\ChannelRepositoryInterface;
-use Sylius\Component\Core\Model\CustomerInterface;
 use Sylius\Component\Core\Model\ShopUserInterface;
 use Sylius\Component\Resource\Factory\FactoryInterface;
 use Sylius\Component\User\Repository\UserRepositoryInterface;
 use Sylius\ShopApiPlugin\Command\Customer\RegisterCustomer;
 use Sylius\ShopApiPlugin\Event\CustomerRegistered;
+use Sylius\ShopApiPlugin\Provider\CustomerProviderInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Webmozart\Assert\Assert;
 
@@ -25,24 +25,24 @@ final class RegisterCustomerHandler
     /** @var FactoryInterface */
     private $userFactory;
 
-    /** @var FactoryInterface */
-    private $customerFactory;
-
     /** @var EventDispatcherInterface */
     private $eventDispatcher;
 
+    /** @var CustomerProviderInterface */
+    private $customerProvider;
+
     public function __construct(
         UserRepositoryInterface $userRepository,
         ChannelRepositoryInterface $channelRepository,
         FactoryInterface $userFactory,
-        FactoryInterface $customerFactory,
-        EventDispatcherInterface $eventDispatcher
+        EventDispatcherInterface $eventDispatcher,
+        CustomerProviderInterface $customerProvider
     ) {
         $this->userRepository = $userRepository;
         $this->channelRepository = $channelRepository;
         $this->userFactory = $userFactory;
-        $this->customerFactory = $customerFactory;
         $this->eventDispatcher = $eventDispatcher;
+        $this->customerProvider = $customerProvider;
     }
 
     public function __invoke(RegisterCustomer $command): void
@@ -50,8 +50,8 @@ public function __invoke(RegisterCustomer $command): void
         $this->assertEmailIsNotTaken($command->email());
         $this->assertChannelExists($command->channelCode());
 
-        /** @var CustomerInterface $customer */
-        $customer = $this->customerFactory->createNew();
+        $customer = $this->customerProvider->provide($command->email());
+
         $customer->setFirstName($command->firstName());
         $customer->setLastName($command->lastName());
         $customer->setEmail($command->email());
diff --git a/src/Provider/ShopUserAwareCustomerProvider.php b/src/Provider/ShopUserAwareCustomerProvider.php
index 8c8dd8ad8..78446374b 100644
--- a/src/Provider/ShopUserAwareCustomerProvider.php
+++ b/src/Provider/ShopUserAwareCustomerProvider.php
@@ -59,7 +59,7 @@ public function provide(string $emailAddress): CustomerInterface
         }
 
         if ($customer->getUser() !== null) {
-            throw new WrongUserException('Customer already registered. Please log in to finish checkout.');
+            throw new WrongUserException('Customer already registered.');
         }
 
         return $customer;
diff --git a/src/Resources/config/services/handler/customer.xml b/src/Resources/config/services/handler/customer.xml
index 7826329e1..500d0c0a8 100644
--- a/src/Resources/config/services/handler/customer.xml
+++ b/src/Resources/config/services/handler/customer.xml
@@ -7,8 +7,8 @@
             <argument type="service" id="sylius.repository.shop_user"/>
             <argument type="service" id="sylius.repository.channel"/>
             <argument type="service" id="sylius.factory.shop_user"/>
-            <argument type="service" id="sylius.factory.customer"/>
             <argument type="service" id="event_dispatcher"/>
+            <argument type="service" id="sylius.shop_api_plugin.provider.customer_provider"/>
             <tag name="messenger.message_handler" />
         </service>
 
diff --git a/tests/Controller/Customer/RegisterApiTest.php b/tests/Controller/Customer/RegisterApiTest.php
index b5608dff0..6688a5004 100644
--- a/tests/Controller/Customer/RegisterApiTest.php
+++ b/tests/Controller/Customer/RegisterApiTest.php
@@ -7,8 +7,11 @@
 use PHPUnit\Framework\Assert;
 use Sylius\Component\Core\Test\Services\EmailCheckerInterface;
 use Sylius\Component\User\Repository\UserRepositoryInterface;
+use Sylius\ShopApiPlugin\Command\Cart\AssignCustomerToCart;
+use Sylius\ShopApiPlugin\Command\Cart\PickupCart;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Messenger\MessageBusInterface;
 use Tests\Sylius\ShopApiPlugin\Controller\JsonApiTestCase;
 use Tests\Sylius\ShopApiPlugin\Controller\Utils\PurgeSpooledMessagesTrait;
 
@@ -50,6 +53,47 @@ public function it_allows_to_register_in_shop_and_sends_a_verification_email_if_
         Assert::assertTrue($emailChecker->hasRecipient('vinny@fandf.com'));
     }
 
+    /**
+     * @test
+     */
+    public function it_allows_to_register_a_customer_if_the_customer_did_a_guest_checkout_already(): void
+    {
+        $this->loadFixturesFromFiles(['channel.yml']);
+
+        $token = 'SDAOSLEFNWU35H3QLI5325';
+
+        /** @var MessageBusInterface $bus */
+        $bus = $this->get('sylius_shop_api_plugin.command_bus');
+        $bus->dispatch(new PickupCart($token, 'WEB_GB'));
+        $bus->dispatch(new AssignCustomerToCart($token, 'vinny@fandf.com'));
+
+        $data =
+<<<JSON
+        {
+            "firstName": "Vin",
+            "lastName": "Diesel",
+            "email": "vinny@fandf.com",
+            "plainPassword": "bananas1234"
+        }
+JSON;
+
+        $this->client->request('POST', '/shop-api/register', [], [], self::CONTENT_TYPE_HEADER, $data);
+
+        $response = $this->client->getResponse();
+        $this->assertResponseCode($response, Response::HTTP_NO_CONTENT);
+
+        /** @var UserRepositoryInterface $userRepository */
+        $userRepository = $this->get('sylius.repository.shop_user');
+        $user = $userRepository->findOneByEmail('vinny@fandf.com');
+
+        Assert::assertNotNull($user);
+        Assert::assertFalse($user->isEnabled());
+
+        /** @var EmailCheckerInterface $emailChecker */
+        $emailChecker = $this->get('sylius.behat.email_checker');
+        Assert::assertTrue($emailChecker->hasRecipient('vinny@fandf.com'));
+    }
+
     /**
      * @test
      */