Area Codes in The United States - Future Expansion of NANP

Future Expansion of NANP

The North American Numbering Plan Administration (NANPA) is now overseen by Neustar, which will probably face the task of adding one or two digits to each number, likely sometime after 2038. During that time, all public and private phone systems within the NANP area will have to be upgraded and reprogrammed (or even replaced) to recognize the new dialing rules.

One plan being considered adds a 1 or 0 either to the beginning or end of the area code, or the beginning of the local 7-digit number (or both), which will require mandatory 11-digit dialing (even for local calls), between any two NANP numbers, well before the transition period. In another proposal, existing codes would be changed to "x9xx" (e.g. San Francisco's 415 would become 4915); once that conversion is complete, the new second digit would be opened for a new range. (Compare PhONE Day in the United Kingdom, which added a "1" to the beginning of area codes in preparation for later using other digits, such as "2", for new area codes.) Other proposals include reallocating blocks of numbers assigned to smaller long distance carriers or unused reserved services.

NANPA previously coordinated an expansion of long-distance carrier access ("dial-around") codes from five digits (such as 10-321) to seven (10-10-321), in 1998. Vertical service codes, such as *69 (callback) and *70 (suspend call waiting), have been designed to allow the use of both two- and three-digit codes.