diff --git a/main.py b/main.py
index 2c60dfc..818e419 100644
--- a/main.py
+++ b/main.py
@@ -340,10 +340,10 @@ class ClientInfo(BaseModel):
 
 class User(BaseModel):
     User_Name: str = Field(..., min_length=1, max_length=120)
-    MobileNo: str = Field(..., min_length=1, max_length=40)
+    MobileNo: str = Field(..., min_length=6, max_length=40)
     MobileNoOrder: int = Field(..., ge=1, le=999)
-    Email: EmailStr
-    Type: str = Field("U", min_length=1, max_length=2)
+    Email: Optional[EmailStr]
+    Type: str = Field("U", min_length=1, max_length=1)
     UserNo: int = Field(..., ge=1, le=999)
     Instructions: str | None = Field(None, max_length=500)
     CallOrder: int = Field(0, ge=0, le=999)
@@ -601,14 +601,33 @@ def _update_client_in_db_from_data(client_id: int, keyrec: KeyRecord, data: dict
         updates: dict[str, object] = {}
 
         def set_text(field_name: str, column: str):
+            """
+            PATCH logic:
+              * field missing → ignore
+              * field present and null → clear (set to "")
+              * field present and "" → clear (set to "")
+              * field present and "text" → update
+            """
+
+            # If field is missing in request, ignore.
             if field_name not in data:
                 return
+
             val = data[field_name]
+
+            # null means clear
             if val is None:
+                updates[column] = ""
                 return
-            sval = str(val).strip()
-            if not sval:
+
+            sval = str(val)
+
+            # empty string means clear
+            if sval.strip() == "":
+                updates[column] = ""
                 return
+
+            # normal update
             updates[column] = sval
 
         def set_int(field_name: str, column: str):