When selecting a number for your WA business account, there are several rules that should be followed:
- A number should be in the international format, accessible from outside of the country.
- Short codes are not allowed, toll-free numbers are allowed if they are in the international format.
- The number should be able to receive a one-time pin through SMS or voice call; a machine answering system shouldn’t be enabled during the 2FA call.
- The number needs to be unique on the WhatsApp platform, not already registered. A phone number that is already registered in the Android, iPhone, or Business Application versions of WhatsApp can be used, if the old account associated with that phone number is properly deleted. A phone number already being used with the WhatsApp Business API cannot be migrated.