---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21266#article
headline: "21266: 'To' and 'From' numbers cannot be the same"
url: https://www.twilio.com/docs/api/errors/21266
inLanguage: en
dateModified: 2026-04-20T06:45:15.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21266: 'To' and 'From' numbers cannot be the same

Log Type: APPLICATION

Log Level: ERROR

## Description

You attempted to send an SMS, but the `To` phone number you supplied is the same as the `From` number.

### Possible causes

You attempted to send an SMS from a Twilio number to itself (putting the same Twilio number in the `To` and `From` parameters).

### Possible solutions

Ensure you are not attempting to send a message from a Twilio number to itself.