# Picking a number for WhatsApp Business

All WhatsApp Business API accounts are based on a valid phone number. The following rules apply: 

* You must own this number and be able to access it during the time your channel is active.
* The number must include a country code and an area code.
* If it is a voice-only capable number, or a landline, it must be able to receive international calls.
* The number must be able to receive international calls or SMS for the channel activation.
* The number needs to be 'clean', which means it mustn't have been registered with another WhatsApp user. If you are using a number for the WhatsApp App and would like to use this in the API, it is possible to migrate the number. Please follow the steps in [WhatsApp phone number: From mobile app to API](https://docs.bird.com/connectivity-platform/getting-started/whatsapp-phone-number-from-mobile-app-to-api)

These types of numbers are accepted:

* Landline numbers that accept international calls
* Mobile numbers
* Virtual Mobile Numbers (VMN); Need to be voice-capable to receive the activation token by call. VMNs can be purchased from MessageBird.

These types of numbers are not accepted: 

* Shortcodes
* Numbers with an IVR (automated call menu) attached to it, unless this can be disabled to receive the activation token.
* Toll-free numbers
* Voice capable numbers unable to receive international calls
* Voice capable numbers that require extra zeros or digits apart from the international number format. A phone number in full international format includes **a plus sign (+) followed by the country code, city code, and local phone number**.

**Note**  If you have switched from the WhatsApp Business App to the API using the same number and are now looking to switch back, please review [WhatsApp phone number: From mobile app to API](https://docs.bird.com/connectivity-platform/getting-started/whatsapp-phone-number-from-mobile-app-to-api)