diff --git a/src/backend/api/models.py b/src/backend/api/models.py
index a22908977a..aa5c14375f 100644
--- a/src/backend/api/models.py
+++ b/src/backend/api/models.py
@@ -69,7 +69,12 @@ class StateChoices(models.TextChoices):
 class User(AbstractBaseUser):
     id = models.UUIDField(primary_key=True, default=uuid4, editable=False)
     name = models.CharField(max_length=150, validators=[MinLengthValidator(3)])
-    email = models.EmailField(max_length=254, unique=True, help_text="Case insensitive")
+    email = models.EmailField(
+        max_length=254,
+        unique=True,
+        help_text="Case insensitive",
+        error_messages={"unique": "Please check the email address and try again."},
+    )
     company_name = models.CharField(max_length=150, blank=True)
     is_active = models.BooleanField(default=True)
     date_joined = models.DateTimeField(auto_now_add=True, editable=False)
diff --git a/src/backend/api/tests/test_views.py b/src/backend/api/tests/test_views.py
index d230f5c18d..69b1ed8988 100644
--- a/src/backend/api/tests/test_views.py
+++ b/src/backend/api/tests/test_views.py
@@ -95,6 +95,45 @@ class TestUserViewSet:
             == "/data/attributes/password"
         )
 
+    @pytest.mark.parametrize(
+        "email",
+        [
+            # Same email, validation error
+            "nonexistentemail@prowler.com",
+            # Same email with capital letters, validation error
+            "NonExistentEmail@prowler.com",
+        ],
+    )
+    def test_users_create_used_email(self, authenticated_client, email):
+        # First user created; no errors should occur
+        user_payload = {
+            "name": "test_email_validator",
+            "password": "newpassword123",
+            "email": "nonexistentemail@prowler.com",
+        }
+        response = authenticated_client.post(
+            reverse("user-list"), data=user_payload, format="json"
+        )
+        assert response.status_code == status.HTTP_201_CREATED
+
+        user_payload = {
+            "name": "test_email_validator",
+            "password": "newpassword123",
+            "email": email,
+        }
+        response = authenticated_client.post(
+            reverse("user-list"), data=user_payload, format="json"
+        )
+        assert response.status_code == status.HTTP_400_BAD_REQUEST
+        assert (
+            response.json()["errors"][0]["source"]["pointer"]
+            == "/data/attributes/email"
+        )
+        assert (
+            response.json()["errors"][0]["detail"]
+            == "Please check the email address and try again."
+        )
+
     def test_users_partial_update(self, authenticated_client, create_test_user):
         new_company_name = "new company test"
         payload = {
diff --git a/src/backend/api/v1/serializers.py b/src/backend/api/v1/serializers.py
index 753152c95b..cd575cb981 100644
--- a/src/backend/api/v1/serializers.py
+++ b/src/backend/api/v1/serializers.py
@@ -180,7 +180,9 @@ class UserCreateSerializer(BaseWriteSerializer):
     def validate_email(self, value):
         normalized_email = value.strip().lower()
         if User.objects.filter(email__iexact=normalized_email).exists():
-            raise ValidationError("User with this email already exists.", code="unique")
+            raise ValidationError(
+                User._meta.get_field("email").error_messages["unique"], code="unique"
+            )
         return value
 
     def create(self, validated_data):