Area code 678 is an overlay serving the greater Atlanta metropolitan area in Georgia, alongside area codes 770 and 404. Introduced in 1998, 678 was created to address the growing need for numbers in the rapidly expanding suburbs of Atlanta. The area includes major cities and communities such as Sandy Springs, Decatur, Roswell, and Alpharetta. Atlanta’s booming tech, finance, and entertainment sectors have made 678 one of the most commonly assigned area codes in the region. Ten-digit dialing is required, and 678 is often found on newer mobile numbers. It has become a modern symbol of Atlanta’s continued growth and urban sprawl.