NPA-NXX (North American Numbering Plan)

North America Public Switched Telephone Networks telephone number management system within the international country code prefix '+1'. North American phone numbers are in the format NPA-NXX-XXX where 'N' is any digit from 2-9, and 'X' is any digit from 0-9. 'NPA' identifies the 3-digit area code, 'NXX' identifies the exchange within the NPA, and 'XXXX' identifies the station within NXX.