List of New Jersey area codes

The area codes in the U.S. State of New Jersey are a component of the North American Numbering Plan.

Area code 201 was the original, sole area code for New Jersey in 1947, when the American Telephone and Telegraph Company (AT&T) devised the first continental telephone numbering plan.

It was also the first area code assigned in the numbering plan.

[1][2][3] This separated the two population centers (Philadelphia suburbs, and New York City suburbs) into distinct call routing systems for out-of-state long-distance calls.

In July 1963 central office code protection was lifted and the use of the area code was mandatory when dialing out of the caller's numbering plan area.

Numbering plan areas and area codes of New Jersey
New Jersey numbering plan areas as shown in the July 1963 NJ Bell telephone directory, when the use of the area code became mandatory.