---
page_type: error
code: 21300
message: "21300: Invalid BYOC trunk SID"
level: ERROR
product: Programmable Voice
---

## Description

You have specified a BYOC trunk SID that is malformed or non-existent.

### Possible Causes

- The SID in question is not formatted correctly. A valid BYOC trunk SID starts with prefix "BY" and is 34 characters in length.
- The BYOC trunk identified by the SID does not exist. If it existed in the past, it has since been removed.
- The BYOC trunk exists but ownership is with a different account.

### Possible Solutions

Make sure you submit the SID of a BYOC trunk that you can locate within your account.