678 Area Code: Atlanta, Georgia

Atlanta's 678 area code is an overlay layered onto the broader Atlanta-metro geography long served by the older 404 and 770. The 678 designation has been filling with allocations since the late 1990s, when the metro's number demand outgrew the older codes. Atlanta itself anchors the directory's records here, on a high ridge above the headwaters of the Chattahoochee in the Piedmont country of north Georgia. The 678 footprint covers the city along with the surrounding cluster of suburban and exurban communities that make up the broader metropolitan area.

In records the directory has compiled for 678 numbers, other Georgia cities — Albany, Columbus, Macon, and Sandy Springs among them — appear regularly. None of those are inside the 678 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Georgia and addresses linked across multiple cities. The directory currently documents 703 distinct prefixes within 678 in detail, a working subset of the prefix population the code carries.

Atlanta's home values run well above the US median, in line with broader Atlanta-metro pricing pressure. Median household income sits above the national reading, the city's median age skews a few years under the US figure, and population places Atlanta among the largest cities in the southeastern United States, the anchor of a metropolitan area that pulls steadily on populations from across the surrounding region. The 678 footprint shares the city's broader demographic profile because the codes overlap.