---
page_type: error
code: 21420
message: "21420: ApplicationSid is not accessible"
level: ERROR
---

## Error - 21420

### ApplicationSid is not accessible

You specified a VoiceApplicationSid or SmsApplicationSid for a new phone number that is not controlled by your account, or is invalid. Please specify an ApplicationSid that you've created in your [Account Dashboard](/user/account/apps).