The North American Numbering Plan (NANP) divides the territories of its members into geographic numbering plan areas (NPAs).
The rules for numbering NPAs do not permit the digits 0 and 1 in the leading position.
NPAs with 9 in the second position are reserved for future format expansion.
Newfoundland was added to the service area when it joined Canada in 1949.
Future area codes are in italic type face.