---
page_type: error
code: 21266
message: "21266: 'To' and 'From' numbers cannot be the same"
level: ERROR
product: Programmable Messaging
---

## 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 (i.e. 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.