# 31301: Registration error

Log Level: ERROR

## Description

This error occurs when registration for incoming call push notifications fails. Set up your push certificate in the Console, register the app with `Voice.register(...)`, and use an Access Token that includes a `VoiceGrant` and a non-empty `identity`.

### Possible causes

* Your app is not set up with a push certificate in the Console, or it is not registering for incoming calls with `Voice.register(...)`.
* The Access Token does not include a `VoiceGrant`, or the API key and secret used to generate the token are incorrect.
* The device token has changed, or the registration has not been refreshed in more than 6 months.
* The Access Token does not include a non-empty `identity`.

### Possible solutions

* Set up the push certificate in the Console and call `Voice.register(...)` when the app launches so the device can receive incoming calls.
* Generate the Access Token with a `VoiceGrant`, and verify that you are using the correct API key and secret pair.
* Re-register the device token whenever it changes, and register again if `Voice.register(...)` was last called more than 6 months ago.
* Make sure the Access Token includes a non-empty `identity`.

#### Additional resources

* [Voice Android SDK FAQ](/docs/voice/sdks/android/faq)
* [Voice Mobile SDKs: Best Practices](/docs/voice/sdks/mobile-best-practices)