Telephone numbers in North America

Canada, the United States and some Caribbean countries use the country calling code 1. Local area codes in these countries are managed by the North American Numbering Plan.

Greenland and Aruba have a country calling code that has the number "2" as first digit, which mostly is used by countries in Africa. All other countries use codes that start with "5".

Country Code: +1
International Call Prefix: 011
Trunk Prefix: 1

In the United States (including its territories), Canada, Bermuda, and 18 Caribbean nations, area codes are regulated by the North American Numbering Plan. Currently, all area codes (officially called numbering plan areas) in the NANP must have 3 digits. Historically, the second digit was always "0" or "1", while the second digit of the 3-digit exchange prefix was never "0" or "1." With the increased demand for area codes because of additional lines, FAX lines, pagers, cell phones, etc., the restrictions on the second digit were lifted in 1995. At the same time, the historic restriction on a local (7-digit) telephone number's second digit, which previously could not be a "0" or "1" (to avoid confusion with area codes), was also lifted. Under the new rules, a telephone number such as (378) 400-1234 is perfectly legal, whereas before 1995 it was not permitted.

Despite being one numbering plan, the cost of calling numbers in the NANP (both from inside and from outside) can vary widely depending on which country of the NANP the code is in. As a result, great care is needed on the part of a caller to avoid unexpectedly large bills.

Not all area codes correspond to a geographical area. Codes 8xx (excluding 811 and 899) with the last two digits matching, such as 800, 888, 877, 866, etc., are reserved for toll-free calls. Code 900 is reserved for premium-rate calls (also known as dial-it services, although such services also exist in some places on a local basis using a particular three-digit prefix following the area code, often "976" or "540"). Area code 710 is reserved for the United States Government. Area code 600 is reserved for national Canadian services.

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