The North American Numbering Plan (NANP) is a telephone numbering plan for World Zone 1, which comprises twenty-five distinct regions in twenty countries primarily in North America, including the Caribbean. Some North American countries, most notably Mexico, do not participate in the NANP.
The North American Numbering Plan (NANP) divides the regions of its member nations into geographic numbering plan areas (NPAs). Each NPA is identified by one or more numbering plan area codes (NPA codes, or area codes), consisting of three digits that are prefixed to each local telephone number having seven digits.
This is a list of North American telephone area codes in effect for the North American Numbering Plan (NANP). The area to which an area code is officially assigned is known as a Numbering Plan Area (NPA). An area code is part of a telephone number in the United States, Canada, and the Caribbean.