diff --git a/app/routers/api_crud_v3.py b/app/routers/api_crud_v3.py
index c7c5a0d..c39824c 100644
--- a/app/routers/api_crud_v3.py
+++ b/app/routers/api_crud_v3.py
@@ -487,9 +487,13 @@ async def post_obj(
 
     # Enforce account ownership AFTER sanitize_payload so the integer account_id goes straight
     # to the DB without conflicting with Vision ID string constraints in the model.
+    # Guard: skip if the model explicitly excludes account_id from DB writes (e.g. event_badge,
+    # event_device — the column does not exist in those tables).
     if not account.super and account.auth_method != 'bypass' and account.account_id:
         if 'account_id' in input_model.__fields__:
-            data_to_insert['account_id'] = account.account_id
+            excluded = getattr(input_model, 'fields_to_exclude_from_db', [])
+            if 'account_id' not in excluded:
+                data_to_insert['account_id'] = account.account_id
 
     if sql_insert_result := sql_insert(data=data_to_insert, table_name=table_name_insert):
         new_obj_id = sql_insert_result
diff --git a/app/routers/api_crud_v3_nested.py b/app/routers/api_crud_v3_nested.py
index 7386305..82c2e2b 100644
--- a/app/routers/api_crud_v3_nested.py
+++ b/app/routers/api_crud_v3_nested.py
@@ -332,9 +332,13 @@ async def post_child_obj(
 
     # Enforce account ownership AFTER sanitize_payload so the integer account_id goes
     # straight to the DB without conflicting with Vision ID string constraints in the model.
+    # Guard: skip if the model explicitly excludes account_id from DB writes (e.g. event_badge,
+    # event_device — the column does not exist in those tables).
     if not account.super and account.auth_method != 'bypass' and account.account_id:
         if 'account_id' in input_model.__fields__:
-            data_to_insert['account_id'] = account.account_id
+            excluded = getattr(input_model, 'fields_to_exclude_from_db', [])
+            if 'account_id' not in excluded:
+                data_to_insert['account_id'] = account.account_id
 
     # Re-inject parent FK last — overrides anything sanitize_payload or the model may have
     # set — ensuring the child is always linked to the correct parent.