# 63110: The phone number registration error

Log Type: APPLICATION

Log Level: ERROR

## Description

This error appears when Twilio cannot finish registering a WhatsApp sender because the phone number is already registered with WhatsApp. It can also appear when Meta does not complete the request code step during registration.

### Possible causes

* The phone number is already registered on WhatsApp.
* Meta request code failed during registration.

### Possible solutions

* Check that the phone number is not already registered for the account or any subaccounts.
* If the number is registered with WhatsApp or the WhatsApp Business app, delete that WhatsApp account before trying again.
* If the number is registered with another WhatsApp Business Platform, turn off Two-Factor Authentication in WhatsApp Manager and register the number again.
* If Meta request code failed, wait 5 minutes before trying again.
* If the number was registered with WhatsApp separately from Twilio, remove the number from that registration before retrying.

#### Additional resources

* [Register WhatsApp senders using the Senders API](/docs/whatsapp/register-senders-using-api)
* [Register WhatsApp senders using Self Sign-up](/docs/whatsapp/self-sign-up)
* [Migrate phone numbers and WhatsApp senders](/docs/whatsapp/migrate-numbers-and-senders)