Area codes 609 and 640

The numbering plan area includes the cities of Trenton, Princeton, Ewing, Hamilton, and southeastern parts of the state and the Jersey Shore, including Atlantic City and Long Beach Island.

In terms of geographic coverage, it is the largest numbering plan area in New Jersey.

By the late 1990s, the proliferation of cell phones and pagers, particularly in the Philadelphia suburbs, Trenton, and in Atlantic City, necessitated a new area code in South Jersey.

The new area code entered service on June 14; permissive dialing of 609 continued across South Jersey until November 14.

With the implementation of the overlay, the New Jersey Board of Public Utilities ordered the removal of central office code protection for a group of central offices between NPA 609 and 856, that had been in effect since the 1999 split to permit seven-digit dialing in the local area to the adjacent NPA.

Numbering plan areas and area codes of New Jersey
Division of New Jersey into two numbering plan area in 1956. Howwever, it was not until July 1963, when New Jersey customers were required to dial the area code when calling to a location in the state, but outside of their own numbering plan area.