---
page_type: error
code: 80304
message: "80304: Not Found Unmanaged Identifier"
level: WARNING
product: Proxy
---

## Warning

### Not Found Unmanaged Identifier

Unmanaged Proxy Identifier not found. Unmanaged identifiers include non-phone number identifiers (e.g., a facebook messenger page id). Possibly you tried to add a participant with a proxy identifier for a channel that is not managed by Twilio or by your Proxy Service.