what area code is 415
Area code 415 is a California telephone area code that was one of the first three original area codes established in California in October 1947.It serves San Francisco and its northern suburbs in Marin County (across the Golden Gate Bridge), and the northeast corner of San Mateo County.rea 415 has been split three times due to the Bay Area's rapid growth: 1  On March 1, 1959, in a three-way split, area code 707 was created for the North Coast (excluding Marin County) and area code 408 for San Jose and the South Bay.