Area code 628 is an overlay for the 415 area, covering San Francisco and parts of Marin County in California. Introduced in 2015, it ensures continued number availability in this densely populated and internationally significant region. While 415 is more iconic, 628 has become common for newer businesses and residents. The region is synonymous with tech innovation, finance, and cultural influence. Ten-digit dialing is mandatory. Though newer, 628 is increasingly tied to the identity of the greater Bay Area.