---
page_type: error
code: 32206
message: "32206: SIP: Invalid From number (caller ID)"
level: ERROR
product: Elastic SIP Trunking
---

## Description

You attempted to initiate an outbound phone call or message, but the 'From' parameter you supplied was not a valid phone number or alphanumeric sender ID.

Twilio accepts phone numbers in [E.164 format](/docs/glossary/what-e164) (i.e. "+1 format"), 10-digit US and Canadian numbers with any combination of non-digit separators, or Alphanumeric Sender IDs (SMS only) with up to 11 alphanumeric characters \[a-zA-Z0-9]. Refer to [this page](https://support.twilio.com/hc/en-us/articles/223133867-Using-Alphanumeric-Sender-ID-with-Messaging-Services) for acceptable characters.

The number must not be on a do-not-originate (DNO) list, and Alpha Sender IDs may not be generic.

### Possible Causes

- You have supplied a phone number that was not in [E.164 format](/docs/glossary/what-e164)
- Your `From` phone number is on a do-not-originate (DNO) list

### Possible Solutions

- Ensure your number is formatted in [E.164 format](/docs/glossary/what-e164)
- Ensure that your `From` number is assigned and not on a do-not-originate (DNO) list.