scope:

The purpose of this document is to consolidate the information contained in earlier industry documents into a single standard document that may be used by the industry as the North American Numbering Plan (NANP) evolves. Further, this document serves as a "snapshot" for anyone interested in numbering issues.

This technical document seeks to document the format and values of telephone numbers in the United States portion of the NANP, thereby coining a "United States Numbering Plan" and a "United States Dialing Plan." It further defines the other telecommunications industry uses of numbers and describes these uses in the United States. The NANP exists under Country Code 1, shared among 19 countries, under the International Telecommunication Union (ITU) Recommendation E.164, "The international public telecommunication numbering plan" (Rec. E.164).