This area code is largely made up of the City and County of San Francisco, California the state’s fourth most populated city, as well as neighboring cities and unincorporated portions of Marin and San Mateo Counties. The make-up of the 415 area code in addition to the City of San Francisco, consists of the cities of Brisbane, Daly City, in San Mateo County and all of Marin County except Dillon Beach and Tomales. Service is provided to these communities through fourteen rate centers, three in San Francisco (with parts in San Mateo County) and eleven in Marin County.
All of the fourteen 415 rate centers are in mandatory Thousand-Block-Number Pooling, which started July 21, 2000. The 415 area code is in LATA 722 and the San Francisco-Oakland-Fremont MSA. The April 2012 Number Resource and Utilization Exhaust Forecast is the 3rd quarter of 2015 with a forecasted demand rate of 24 codes per year.