Area codes 864 and 821 are telephone area codes in the North American Numbering Plan (NANP) for the western third of the U.S. state of South Carolina. The numbering plan area (NPA) comprises the areas of Greenville, Spartanburg, Anderson, and twelve surrounding counties. Other cities in the 864/821 territory include Clemson, Gaffney, Greer, and Mauldin. It is largely coextensive with the Upstate region.
The area code was created in a division of numbering plan area 803 on December 3, 1995.[1]
Projections of 2021 anticipated the requirement of relief from telephone number exhaustion in the Upstate region with a new area code for 2024 or 2025.[2] [3] On November 28, 2022, the NANP Administrator set the implementation target for area code 821 to mid-January 2024 by creation of an all-service overlay complex, approved by the Public Service Commission of South Carolina, requiring ten-digit dialing. Permissive calling started there and ten-digit dialing became mandatory in July 2024.[4] After mid-August 2024, new 821 numbers became assignable.