Area codes 973 and 862

The numbering plan area (NPA) comprises the counties, or parts, of Bergen, Essex, Hudson, Morris, Passaic, Sussex and Union Counties.

Cities in this service area include Newark, Paterson, Clifton, Passaic, Montclair, Morristown, Parsippany, Dover, Maplewood, and The Oranges.

Due to the expansion of cell phones, pagers, and fax machines in the 1990s, the area code experienced the possible exhaustion of the numbering pool.

For relief, the numbering plan area was assigned a second area code 862 in an overlay plan, making ten-digit dialing mandatory on December 1, 2001.

[3][full citation needed] Verizon, the main telephone provider in the region, pressed for an overlay in order to spare North Jerseyans the expense and burden of having to change their numbers for the second time in a decade.