Mobile virtual numbers work the same as local numbers but are issued separately by the mobile regulatory range. Like local numbers, also known as DID numbers, these numbers may or may not be bound to a specific geographical location. In addition paperwork requirements for mobile numbers, with a wider range of availability making them easier than DID numbers to obtain. Calls made to mobile numbers are not free and costs depend on where the call is coming from. Toll free numbers normally cost more than a mobile number with the AVOXI customer paying for the full leg of the call.