August 2, 1997, area code 650 was created; the partition approximately followed the boundary between San Francisco, which (along with Marin County) kept 415, and San Mateo County to the south, which received the new code. Deviations from the county line included a very small area east of the San Francisco Golf Club, which was changed to 650, and portions of Brisbane and Daly City, which remained in 415. On February 21, 2015, the numbering plan area was transitioned to an overlay plan by adding area code 628 to the same service area for new numbers, making ten-digit dialing mandatory in the area, with eleven-digit dialing necessary from landlines. Service area City and County of San Francisco San Francisco Marin County Bel Marin Keys Belvedere Black Point-Green Point Bolinas California Park Corte Madera Dogtown Fairfax Greenbrae Inverness Park Inverness Kentfield Lagunitas-Forest Knolls Larkspur Lucas Valley-Marinwood Manor Marconi Marin City Marshall McNears Beach Mill Valley Muir Beach Nicasio Novato Olema Paradise Cay Point Reyes Station Ross San Anselmo San Geronimo San Quentin San Rafael Santa Venetia Sausalito Sleepy Hollow Stinson Beach Strawberry Tamalpais-Homestead Valley Tiburon Woodacre San Mateo County Brisbane Daly City See also List of California area codes List of NANP area codes References External links List of exchanges from AreaCodeDownload.com, 415 Area Code 415 Culture of San Francisco 415 Marin County, California Northern California Telecommunications-related introductions in 1947