# 22108: Invalid Application SID

Log Level: ERROR

## Description

You attempted to configure a phone number with an invalid Application SID.

### Possible causes

* The SID is not a 34-character string that is prefixed with "AP".
* Invalid SMS Application SID provided in request
* Invalid Voice Application SID provided in request
* The Application resource identified by the SID does not exist anymore or does not belong to your account.

### Possible solutions

Please specify an Application SID you've created in your [Account Dashboard](https://www.twilio.com/user/account/apps).