diff --git a/apps/pm/serializers.py b/apps/pm/serializers.py
index 38317ef4..9733d25f 100644
--- a/apps/pm/serializers.py
+++ b/apps/pm/serializers.py
@@ -24,6 +24,9 @@ class UtaskSerializer(CustomModelSerializer):
     class Meta:
         model = Utask
         fields = '__all__'
+        extra_kwargs = {
+            'number': {"required": False}
+        }
 
     def create(self, validated_data):
         if not validated_data.get('number', None):