Area code 864

34°39′N 82°20′W / 34.650°N 82.333°W / 34.650; -82.333

Area code 864 is a telephone area code 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 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 starts there.^[4] After mid-July 2024, callers continuing to dial the old method will hear recorded messages informing them to use the new method, and seven-digit local calling throughout the state will be over. Come mid-August 2024, new 821 numbers will get assigned.