http://www.nanpa.com/
NANPA = North American Numbering Plan Administration
From the website
This site provides information about the North American Numbering Plan (NANP) and its administration. The NANP is the numbering plan for the Public Switched Telephone Network for Canada, the US and its territories, and the Caribbean.
The NANP is used for any phone numbers served by country code +1, which includes Canada and The USA, as well as:
Anguilla, Barbuda, Bahamas, Barbados, Bermuda, British Virgin Islands, Cayman Islands, Dominica, Dominican Republic, Grenada, Jamaica, Montserrat, Puerto Rico, St. Kitts & Nevis, St. Lucia, St. Vincent & Grenadines, Trinidad & Tobago, Turks & Caicos Islands.
April 7, 2023
Phone System 