diff --git a/apps/authentication/api/v1/serializers/serializer.py b/apps/authentication/api/v1/serializers/serializer.py
index a71f3fb..aff0caf 100644
--- a/apps/authentication/api/v1/serializers/serializer.py
+++ b/apps/authentication/api/v1/serializers/serializer.py
@@ -109,18 +109,24 @@ class UserSerializer(serializers.ModelSerializer):
 
     def validate(self, attrs):
         mobile = attrs['mobile']
-        username = attrs['username']
+        if 'username' in attrs.keys():
+            username = attrs['username']
 
         if not self.instance:
-            if self.Meta.model.objects.filter(Q(mobile=mobile) | Q(username=username)).exists():
+            if self.Meta.model.objects.filter(
+                    Q(mobile=mobile) | Q(username=attrs['username'])
+            ).exists():
                 raise UserExistException()
+
         elif self.instance:
             if self.instance.mobile != mobile:
                 if self.Meta.model.objects.filter(mobile=mobile).exists():
                     raise UserExistException()
-            if self.instance.username != username:
-                if self.Meta.model.objects.filter(username=username).exists():
-                    raise UserExistException()
+
+            if 'username' in attrs.keys():
+                if self.instance.username != attrs['username']:
+                    if self.Meta.model.objects.filter(username=attrs['username']).exists():
+                        raise UserExistException()
 
         return attrs
 
diff --git a/logs/django_requests.log b/logs/django_requests.log
index 543bd9e..6ba38d6 100644
--- a/logs/django_requests.log
+++ b/logs/django_requests.log
@@ -43,3 +43,5 @@
 [2025-10-27 16:47:09,174] INFO django.utils.autoreload | IP: - | Path: - | D:\Project\Rasaddam_Backend\apps\authentication\api\v1\serializers\serializer.py changed, reloading.
 [2025-10-27 16:47:13,725] INFO django.utils.autoreload | IP: - | Path: - | Watching for file changes with StatReloader
 [2025-10-27 16:49:53,321] INFO django.utils.autoreload | IP: - | Path: - | D:\Project\Rasaddam_Backend\apps\authentication\api\v1\serializers\serializer.py changed, reloading.
+[2025-10-27 16:49:55,766] INFO django.utils.autoreload | IP: - | Path: - | Watching for file changes with StatReloader
+[2025-10-27 17:04:59,459] INFO django.utils.autoreload | IP: - | Path: - | D:\Project\Rasaddam_Backend\apps\authentication\api\v1\serializers\serializer.py changed, reloading.