Area codes 415 and 628 are telephone area codes in the

North American Numbering Plan The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international calling ...

(NANP) for the city of

San Francisco San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17th ...

and its northern suburbs in Marin County (across the

Golden Gate The Golden Gate is a strait on the west coast of North America that connects San Francisco Bay to the Pacific Ocean. It is defined by the headlands of the San Francisco Peninsula and the Marin Peninsula, and, since 1937, has been spanned by t ...

), and the northeast corner of San Mateo County in the U.S. state of

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. Area code 415 was one of the eighty-six

original North American area codes The original North American area codes were established by the American Telephone & Telegraph Company (AT&T) in 1947, following the demonstration of regional Operator Toll Dialing during the World War II period. The program had the goal of speedin ...

established in 1947, but modified in geographic configuration later. Area code 628 was assigned in 2015 to form an overlay in that numbering plan area in mitigation of central office prefix exhaustion.

History

When the North American Numbering Plan was installed by AT&T for Operator Toll Dialing in 1947, the state of

was divided into three numbering plan areas (NPAs) arranged as geographical zones in the southern part, the central part, and the northern part of the state. Area code 415 was assigned to central California, south of area code 916, and north of area code 213. It stretched from

Sacramento ) , image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg , mapsize = 250x200px , map_caption = Location within Sacramento ...

in the north to Bakersfield in the south. In 1950, the boundaries of the numbering plan area were redrawn to produce a division of the northern and central parts along a north-south-running dividing line. Numbering plan area 415 became the coastal region from the North Coast to the

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

border, while 916 was redrawn to comprise the northeastern corner of the state. As part of this realignment, Sacramento was renumbered from area code 415 to 916, and Bakersfield to 213. With the preparations for nation-wide

direct distance dialing Direct distance dialing (DDD) is a telecommunication service feature in North America by which a caller may, without operator assistance, call any other user outside the local calling area. Direct dialing by subscribers typically requires extra d ...

(DDD) in the early 1950s,

area code 318 Area code 318 is a telephone area code in the North American Numbering Plan (NANP) for the northern and central parts of the U.S. state of Louisiana. The area code was created in 1957 in a split of Louisiana's original area code 504. Originally ...

was temporarily used in the San Francisco area, initially by customers in Englewood, New Jersey, participating in the first customer trials to reach the city, as well as some areas north of the

. In 1953, the entire Bay Area was "reunited" in using area code 415. Area code 415 has been split three times due to the Bay Area's rapid economic growth and demand for telecommunication services: * On March 1, 1959,

area code 707 Area code 707 is a telephone area code in the North American Numbering Plan (NANP) for the northwestern part of the U.S. state of California. It was created by a split of area code 415 on March 1, 1959. It serves part of the northern San Francis ...

was created from the northern part, and area code 408 was created for San Jose, the South Bay, the

Monterey Bay Monterey Bay is a bay of the Pacific Ocean located on the coast of the U.S. state of California, south of the San Francisco Bay Area and its major city at the south of the bay, San Jose. San Francisco itself is further north along the coast, by ...

, and the

Salinas Valley The Salinas Valley is one of the major valleys and most productive agricultural regions in California. It is located west of the San Joaquin Valley and south of San Francisco Bay and the Santa Clara Valley. The Salinas River, which geologically ...

. (408 has since been split to 831 and overlaid with 669.) * On September 2, 1991, area code 510 was created for the

East Bay The East Bay is the eastern region of the San Francisco Bay Area and includes cities along the eastern shores of the San Francisco Bay and San Pablo Bay. The region has grown to include inland communities in Alameda and Contra Costa counties ...

, including Oakland. (510 has since been split to 925 and was overlaid by 341 in 2019.) * On 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 Brisbane ( ) is the capital and most populous city of the Australian state of Queensland, and the third-most populous city in Australia and Oceania, with a population of approximately 2.6 million. Brisbane lies at the centre of the South ...

and Daly City, which remained in 415. On February 21, 2015, the numbering plan area was transitioned to an

overlay plan Overlay may refer to: Computers * Overlay network, a computer network which is built on top of another network * Hardware overlay, one type of video overlay that uses memory dedicated to the application *Another term for exec, replacing one proce ...

by adding area code 628 to the same service area for new numbers, making

ten-digit dialing Ten-digit dialing is a telephone dialing procedure in the countries and territories that are members of the North American Numbering Plan (NANP). It is the practice of including the area code of a telephone number when dialing to initiate a telep ...

mandatory in the area, with eleven-digit dialing necessary from landlines.

Service area

City and County of San Francisco

Marin County

* Bel Marin Keys * Belvedere * Black Point-Green Point *

Bolinas Bolinas is an unincorporated coastal community and census-designated place in Marin County, California, United States. As of the 2020 census it had a population of 1,483. It is located on the California coast, approximately (straight line dist ...

* California Park * Corte Madera *

Dogtown Dogtown or Dog Town may refer to: Entertainment * ''Dogtown'' (film), a 1997 film * "Dogtown" (''The Simpsons''), a 2017 season episode * '' DogTown'', a National Geographic Channel series * ''Dogtown'', a 2006 television show, starring Geraldine ...

* Fairfax *

Greenbrae Greenbrae is a small unincorporated community in Marin County, California. It is located south-southeast of downtown San Rafael, at an elevation of 33 feet (10 m), located adjacent to U.S. Route 101 at the opening of the Ross Valley. Part of ...

* Inverness Park * Inverness *

Kentfield Kentfield (formerly Ross Landing, Tamalpais, and Kent) is a census-designated place (CDP) in Marin County, California, United States, just north of San Francisco. Kentfield is located southwest of downtown San Rafael, at an elevation of 115 fee ...

* Lagunitas-Forest Knolls * Larkspur * Lucas Valley-Marinwood * Manor * Marconi *

Marin City Marin City is an unincorporated community and census-designated place (CDP) in Marin County, California, United States. As of the 2020 census, it had a population of 2,993, up from 2,666 in 2010. It is located northwest of downtown Sausalito, ...

Marshall Marshall may refer to: Places Australia * Marshall, Victoria, a suburb of Geelong, Victoria Canada * Marshall, Saskatchewan * The Marshall, a mountain in British Columbia Liberia * Marshall, Liberia Marshall Islands * Marshall Islands, an i ...

* McNears Beach * Mill Valley * Muir Beach *

Nicasio Nicasio ( ; Spanish for " Nicasius") is an unincorporated community and census-designated place in Marin County, California, United States. It is located west-southwest of Novato, at an elevation of . As of the 2020 census the CDP population w ...

Novato Novato ( Spanish for "Novatus") is a city in Marin County, California, in the North Bay region of the Bay Area. At the 2020 census, Novato had a population of 53,225. History What is now Novato was originally the site of several Coast Miwok ...

* Olema * Paradise Cay * Point Reyes Station * Ross * San Anselmo * San Geronimo * San Quentin * San Rafael * Santa Venetia *

Sausalito Sausalito (Spanish for "small willow grove") is a city in Marin County, California, United States, located southeast of Marin City, south-southeast of San Rafael, and about north of San Francisco from the Golden Gate Bridge. Sausalito's ...

* Sleepy Hollow * Stinson Beach * Strawberry *

Tamalpais-Homestead Valley Tamalpais-Homestead Valley is a census-designated place (CDP) in Marin County, California, United States. The population was 11,492 at the 2020 census. Geography Tamalpais-Homestead Valley is located at . It is bordered by Mill Valley to the nort ...

* Tiburon * Woodacre

San Mateo County

* Daly City

References

External links

List of exchanges from AreaCodeDownload.com, 415 Area Code
{{coord, 38, -122.6, region:US-CA_type:adm2nd, display=title 415 Culture of San Francisco 415 Marin County, California Northern California Telecommunications-related introductions in 1947