Area code 864
Area code 864 is a telephone area code in the North American Numbering Plan (NANP) for the U.S. state of South Carolina. The numbering plan area (NPA) comprises the areas of Greenville, Spartanburg, Anderson, and twelve surrounding counties in upstate South Carolina. Other cities in the 864 territory include Clemson, Gaffney, Greer and Mauldin. The area code was split from area code 803 on December 3, 1995. Until then, South Carolina had been one of the most populous states served by just one area code. When area code 803 was overlaid with area code 839 in May  2020, 864 became the last area of South Carolina that has not been overlaid. As such, it is one of the few urbanized area codes where seven-digit dialing is still possible. Under projections of 2021, it will likely stay that way through about 2024, by which point the upstate will also require an overlay area code and ten-digit dialing would become a statewide requirement.