diff --git a/src/Entity/User.php b/src/Entity/User.php
index 88c2500..687abf7 100755
--- a/src/Entity/User.php
+++ b/src/Entity/User.php
@@ -18,6 +18,7 @@ use App\Form\Type\User\ChangePasswordFormType;
 use App\Form\Type\User\EditProfileFormType;
 use App\Repository\UserRepository;
 use App\Validator\Constraints\User\MembershipPaid;
+use App\Validator\Constraints\User\UniqueUser;
 use Carbon\Carbon;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
@@ -44,7 +45,8 @@ use function Symfony\Component\String\u;
 #[ORM\Index(columns: ['lost_password_token'])]
 #[ORM\Table(name: '`user`')] // we also need escaping here
 #[ORM\EntityListeners([UserListener::class])]
-#[UniqueEntity('email', groups: [AccountCreateStep1FormType::class, ChangeLoginFormType::class, 'Default'])]
+#[UniqueUser(groups: [AccountCreateStep1FormType::class, ChangeLoginFormType::class])]
+#[UniqueEntity('email', groups: ['Default'])]
 #[MembershipPaid]
 class User implements UserInterface, PasswordAuthenticatedUserInterface, ImageInterface, EquatableInterface
 {
diff --git a/src/MessageHandler/Command/Product/CreateGroupInvitationMessageHandler.php b/src/MessageHandler/Command/Product/CreateGroupInvitationMessageHandler.php
index da39fd9..68c3290 100644
--- a/src/MessageHandler/Command/Product/CreateGroupInvitationMessageHandler.php
+++ b/src/MessageHandler/Command/Product/CreateGroupInvitationMessageHandler.php
@@ -58,6 +58,9 @@ final class CreateGroupInvitationMessageHandler
             $user = $this->userManager->getStep1User($message->email);
             $this->userManager->save($user, true);
             $isNewUser = true;
+        } elseif (!$user->isEmailConfirmed()) {
+            $this->userManager->refreshConfirmationToken($user);
+            $isNewUser = true;
         }
 
         // now create the invitation to the group.
diff --git a/src/MessageHandler/Command/Security/AccountCreateStep1CommandHandler.php b/src/MessageHandler/Command/Security/AccountCreateStep1CommandHandler.php
index 6a91d81..ecbbdbc 100644
--- a/src/MessageHandler/Command/Security/AccountCreateStep1CommandHandler.php
+++ b/src/MessageHandler/Command/Security/AccountCreateStep1CommandHandler.php
@@ -9,6 +9,7 @@ use App\Entity\User;
 use App\Mailer\AppMailer;
 use App\Mailer\Email\Security\CreateAccountStep1Email;
 use App\Message\Command\Security\AccountCreateStep1Command;
+use App\Repository\UserRepository;
 use Symfony\Component\Messenger\Attribute\AsMessageHandler;
 
 #[AsMessageHandler]
@@ -20,6 +21,7 @@ final class AccountCreateStep1CommandHandler
     public function __construct(
         private readonly UserManager $userManager,
         private readonly AppMailer $appMailer,
+        private readonly UserRepository $userRepository,
     ) {
     }
 
@@ -31,6 +33,17 @@ final class AccountCreateStep1CommandHandler
      */
     public function __invoke(AccountCreateStep1Command $message): void
     {
+        $existingUser = $this->userRepository->findOneByEmail($message->email);
+        if ($existingUser instanceof User) {
+            if (!$existingUser->isEmailConfirmed()) {
+                $this->userManager->refreshConfirmationToken($existingUser);
+                $this->userManager->save($existingUser, true);
+                $this->appMailer->send(CreateAccountStep1Email::class, ['user' => $existingUser]);
+
+                return;
+            }
+        }
+
         $user = new User();
         $user->setEmail($message->email);
         $this->userManager->refreshConfirmationToken($user);
diff --git a/src/Validator/Constraints/User/UniqueUser.php b/src/Validator/Constraints/User/UniqueUser.php
new file mode 100644
index 0000000..c3f7159
--- /dev/null
+++ b/src/Validator/Constraints/User/UniqueUser.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Validator\Constraints\User;
+
+use Symfony\Component\Validator\Constraint;
+
+#[\Attribute(\Attribute::TARGET_CLASS)]
+final class UniqueUser extends Constraint
+{
+    public string $message = 'validator.user.unique.message';
+
+    public function getTargets(): string
+    {
+        return self::CLASS_CONSTRAINT;
+    }
+}
diff --git a/src/Validator/Constraints/User/UniqueUserValidator.php b/src/Validator/Constraints/User/UniqueUserValidator.php
new file mode 100644
index 0000000..be1daf4
--- /dev/null
+++ b/src/Validator/Constraints/User/UniqueUserValidator.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Validator\Constraints\User;
+
+use App\Entity\User;
+use App\Repository\UserRepository;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+use Symfony\Component\Validator\Exception\UnexpectedValueException;
+
+final class UniqueUserValidator extends ConstraintValidator
+{
+    public function __construct(
+        private readonly UserRepository $userRepository,
+    ) {
+    }
+
+    public function validate(mixed $value, Constraint $constraint): void
+    {
+        if (!$constraint instanceof UniqueUser) {
+            throw new UnexpectedTypeException($constraint, UniqueUser::class);
+        }
+
+        if (!$value instanceof User) {
+            throw new UnexpectedValueException($value, User::class);
+        }
+
+        $existingUser = $this->userRepository->findOneByEmail($value->getEmail());
+
+        if (null === $existingUser) {
+            return;
+        }
+
+        if (!$existingUser->isEmailConfirmed()) {
+            return;
+        }
+
+        $this->context->buildViolation($constraint->message)
+            ->atPath('email')
+            ->addViolation();
+    }
+}
diff --git a/tests/TestReference.php b/tests/TestReference.php
index f0f249a..ed3efda 100644
--- a/tests/TestReference.php
+++ b/tests/TestReference.php
@@ -9,7 +9,7 @@ final class TestReference
     // common
     public const UUID_404 = '1ed7a2a8-0a77-6dbc-a404-040404040404'; // valid UUID for 404 pages
     public const VALIDATION_ERROR_BLANK = 'This value should not be blank';
-    public const VALIDATION_ERROR_ALREADY_USED = 'This value is already used';
+    public const VALIDATION_ERROR_ALREADY_USED = 'validator.user.unique.message';
 
     // EasyAdmin
     public const ADMIN_URL = '/admin?crudAction=%s&crudControllerFqcn=%s';
diff --git a/translations/user/validators.fr.xlf b/translations/user/validators.fr.xlf
index 232d9a5..cc175b2 100644
--- a/translations/user/validators.fr.xlf
+++ b/translations/user/validators.fr.xlf
@@ -11,6 +11,11 @@
             <target>Veuillez remplir ce champ</target>
         </trans-unit>
 
+        <trans-unit id="abcdef" resname="validator.user.unique.message">
+            <source>validator.user.unique.message</source>
+            <target>Cette valeur est déjà utilisée.</target>
+        </trans-unit>
+
     </body>
   </file>
 </xliff>