---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21300#article
headline: "21300: Invalid BYOC trunk SID"
url: https://www.twilio.com/docs/api/errors/21300
inLanguage: en
dateModified: 2026-03-11T18:38:39.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21300: Invalid BYOC trunk SID

Log Type: APPLICATION

Log Level: ERROR

## 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.