Area code 315 was one of the
original North American area codes created in 1947, when it was assigned to a numbering plan area (NPA) in central New York state that extended from the Canadian border with
Ontario and
Quebec southward to the
Pennsylvania state line, including
Binghamton and Syracuse. During 1954, its southern portion, including Binghamton, was combined with the southeastern corner of
numbering plan area 716 in an
area code split that created
area code 607. New York State regulators announced that 315 was threatened by numbering exhaustion for the third quarter of 2010. The New York State Public Service Commission at the time weighed two options, an overlay plan or a split plan. A numbering plan area division would have included a north-south arrangement, dividing
Oswego County and the north from 315, or an east-west division, with Oswego and
Onondaga forming the boundary. Regulators met to discuss a second code in the 315 region. Due to economic conditions, assignable numbers were not depleted during the third quarter of 2010 as projected. The revised exhaustion was estimated for 2017. On March 11, 2017, area code 680 was introduced, creating the first overlay in the upstate region. Since 2017, telephone callers must dial ten digits for local calls for using most telephone services including
Verizon and
Charter Spectrum. Attempts to make a seven-digit call with these services activates an intercept message reminding them of the new rule. As of January 12, 2021, there were still some smaller phone services whose customers were still able to use seven digit dialing within area code 315 and connect to the person they were dialing. As of 2020, very few if any numbers in the 680 area code were in use. On March 15, 2022, a proclamation by Syracuse Mayor
Ben Walsh and
Onondaga County Executive Ryan McMahon declared recognition of '315 day'. ==Service area==