---
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headline: "80404: Participant Identifier Invalid"
url: https://www.twilio.com/docs/api/errors/80404
inLanguage: en
dateModified: 2026-03-11T22:03:37.000Z
author:
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  name: Twilio Developer Education Team
publisher:
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  name: Twilio
---

# 80404: Participant Identifier Invalid

Log Type: APPLICATION

Log Level: ERROR

## Description

Participant identifier provided does not appear to be a valid, reachable phone number.

### Possible causes

The participant's number passed in the participant creation is incorrect.

### Possible solutions

Pass a valid participant's number in [E.164 format](/docs/glossary/what-e164).