---
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"@id": https://www.twilio.com/docs/api/errors/32101#article
headline: "32101: SIP: Invalid phone number"
url: https://www.twilio.com/docs/api/errors/32101
inLanguage: en
dateModified: 2026-03-11T20:01:16.000Z
author:
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  name: Twilio Developer Education Team
publisher:
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  name: Twilio
---

# 32101: SIP: Invalid phone number

Log Type: APPLICATION

Log Level: WARNING

## Description

SIP: Invalid phone number

### Possible causes

The called number is not a valid [E.164](/docs/glossary/what-e164) number.

### Possible solutions

Make sure that any phone number sent via SIP to Twilio is always E.164-formatted.