Area Code 415 History:
Area code 415 was put into service. In 1959 area code 415 was split to form area codes 408 and 707. In 1991 area code 415 was split to form area code 510. In 1997 area code 415 was split to form area code 650.
Area code 628 has been approved by The California Public Utilities Commission as an overlay of area code 415, with an implementation date of March 21, 2015.
Ten digit dialing (area code + seven digit number) will be necessary in the 415/628 overlay because different homes in the same geographic area can have the same seven digit phone number but each would have a different area code.
Counties in California within area code 415 include:
Marin County, and San Francisco County.
Major cities or places in California within area code 415 include:
Area code 415 serves the larger communities of Novato, San Anselmo, San Francisco, and San Rafael, most of Marin County and all of San Francisco County.