---
page_type: error
code: 21213
message: "21213: Caller phone number is required"
level: ERROR
---

## Error - 21213

### 'From' phone number is required

You attempted to initiate an outbound phone call, but you forgot to include a 'From' parameter. The 'From' parameter is required, and tells Twilio what Caller ID to use for the phone call.