| Area Code | 821 |
| State | South Carolina |
| Current Time in Area Code 821 | 821> EST |
| Timezone | Eastern Standard Time |
| Regional Market Area | Upstate South Carolina |
| Metro Area(s) | Gaffney, SC Greenville-Anderson, SC Greenwood, SC Seneca, SC Spartanburg, SC Union, SC |
| Population (2020) | 1540293 |
| Adjacent Area Codes | 704,706,762,803,828,839,864,980 |
| Overlay Area Codes | 864 |
| Abbeville County |
| Anderson County |
| Cherokee County |
| Greenville County |
| Greenwood County |
| Laurens County |
| Mccormick County |
| Oconee County |
| Pickens County |
| Saluda County |
| Spartanburg County |
| Union County |
| Greenville |
| Greer |
| Spartanburg |