of New Jersey grew during the 1980s, the northeastern section of the state lost sizable portions of its population due to the decline of its major cities, including Newark, Paterson, Clifton, and Elizabeth. On June 8, 1991, area code 908 was created by a split of the 201 numbering plan area; it primarily serves the north-central regions of the state. Within four years, 201 was close to exhaustion once again due to the proliferation of cell phones, pagers and fax machines. On June 1, 1997, Essex and Passaic counties, home to Newark and Paterson, respectively, the state's largest and third-largest cities, as well as Morris and Sussex counties were split off with area code 973. This left Hudson and Bergen counties, the two most densely populated counties in the state and the closest to New York City, as the only counties in the 201 plan area. Although the 1997 split was intended as a long-term solution, demand for new numbers continued in Hudson and Bergen counties, and another area code became necessary. Verizon, the dominant telephone company in New Jersey, lobbied for an overlay rather than a split. Overlays were a new concept at the time, and were controversial because they required implementation of ten-digit dialing. However, Verizon wanted to spare its customers the burden of changing telephone numbers. Area code 551 was created in 2001 to overlay 201, along with area codes 862 and 848, which overlay area codes 973 and 732, respectively. With the implementation of the overlay area codes on December 1, 2001, ten-digit dialing became mandatory in Northern New Jersey. See also List of North American Numbering Plan area codes References External links 201 201 201 201 201 201 Telecommunications-related introductions in 2001 Telecommunications-related introductions in 1947