diff --git a/litellm/router.py b/litellm/router.py
index b78298ff84c..b275c264ebc 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -8598,7 +8598,9 @@ class Router:
         # No match found
         return None
 
-    def map_team_model(self, team_model_name: str, team_id: str) -> Optional[str]:
+    def map_team_model(
+        self, team_model_name: Optional[str], team_id: str
+    ) -> Optional[str]:
         """
         Check if team_model_name resolves to team-specific deployments.
 
@@ -8606,6 +8608,11 @@ class Router:
         sibling deployments via team_id filtering, instead of collapsing to a
         single internal model_name.
 
+        When team_model_name is None (e.g. vector store / file endpoints that
+        don't include a model in their request), returns the first matching
+        team deployment's team_public_model_name so the router can inject BYOK
+        credentials from the team-scoped deployment.
+
         Returns:
         - str: the team_model_name if team deployments exist for this team
         - None: if no team-specific model is found
@@ -8615,6 +8622,13 @@ class Router:
             return None
         for model in models:
             if model.get("model_info", {}).get("team_id") == team_id:
+                if team_model_name is None:
+                    # No model was specified (e.g. vector store endpoints).
+                    # Return the deployment's public model name so the router
+                    # can route to it and inject the BYOK API key.
+                    return model.get("model_info", {}).get(
+                        "team_public_model_name"
+                    ) or model.get("model_name")
                 return team_model_name
 
         # No team-scoped deployment found; wildcard/pattern routes are