NANP (North American Numbering Plan)

Invented in 1947 by AT&T and Bell Telephone Laboratories (now Lucent). The NANP assigns area codes and sets rules for calls to be routed across North America (i.e. the US and Canada). The new one, put into effect in January, 1995 has one major change: The middle number in a North American area code no longer is required to be a 1 or a 0; rather, it can range between 0 and 9. NANP numbers are 10 digits in length, in the format NXX-NXX-XXXX. The first three digits are the NPA code (i.e., area code). The second three are the central office code or central office prefix, and the last four are the line number. NANP numbers conform to E.164, which is the ITU-T (International Telecommunication Union) international standard for numbering plans. NANP administration was shifted from Bell Labs to Bellcore, when it was formed in 1986. Due to Bellcore's obvious conflict of interest, responsibility was shifted to NANC (North American Numbering Council) in 1995; it was shifted again in 1997 to Lockheed Martin. In November, 1999, it was shifted to NeuStar Inc., when it was discovered that Lockheed Martin had a conflict of interest. NeuStar originally was an independent business unit of Lockheed Martin, but was spun off in order to resolve the conflict.