Area codes 415 and 628 are

telephone A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into el ...

area code A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, re ...

s 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 language, Spanish for "Francis of Assisi, 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 List of Ca ...

and its northern suburbs in

Marin County Marin County is a county located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 census, the population was 262,231. Its county seat and largest city is San Rafael. Marin County is a ...

(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 ...

), and the northeast corner of

San Mateo County San Mateo County ( ), officially the County of San Mateo, is a county located in the U.S. state of California. As of the 2020 census, the population was 764,442. Redwood City is the county seat, and the third most populated city following Dal ...

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 ...

. 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 speedi ...

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 AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile tel ...

for

Operator Toll Dialing Operator Toll Dialing was a telephone call routing and toll-switching system for the Bell System and the independent telephone companies in the United States and Canada that was developed in the 1940s. It automated the switching and billing of lon ...

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 Area codes 213 and 323 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of California. They are assigned to a numbering plan area (NPA) that comprises, roughly, the area of central Los Angeles, and includes ...

. 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 Bakersfield is a city in Kern County, California, United States. It is the county seat and largest city of Kern County. The city covers about near the southern end of the San Joaquin Valley and the Central Valley (California), Central Valley r ...

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 Idah ...

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 Englewood is a city in Bergen County, in the U.S. state of New Jersey, which at the 2020 United States census had a population of 29,308. Englewood was incorporated as a city by an act of the New Jersey Legislature on March 17, 1899, from po ...

, 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 The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica ...

, 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 geologicall ...

. (408 has since been split to 831 and overlaid with 669.) * On September 2, 1991,

area code 510 Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while ''surface area'' refers to the area of an ...

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 countie ...

, including

Oakland Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast of the United States, West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third ...

. (510 has since been split to 925 and was overlaid by 341 in 2019.) * On August 2, 1997,

area code 650 Area code 650 is a telephone area code in the North American Numbering Plan (NANP) for the San Francisco Bay Area in the U.S. state of California. It was split from area code 415 on August 2, 1997, and includes most of San Mateo County (except t ...

was created; the partition approximately followed the boundary between San Francisco, which (along with Marin County) kept 415, and

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 states and territories of Australia, Australian state of Queensland, and the list of cities in Australia by population, third-most populous city in Australia and Oceania, with a populati ...

and

Daly City Daly City () is the second most populous city in San Mateo County, California, United States, with population of 104,901 according to the 2020 census. Located in the San Francisco Bay Area, and immediately south of San Francisco (sharing its ...

, 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 * California Park * Corte Madera * Dogtown *

Fairfax Fairfax may refer to: Places United States * Fairfax, California * Fairfax Avenue, a major thoroughfare in Los Angeles, California * Fairfax District, Los Angeles, California, centered on Fairfax Avenue * Fairfax, Georgia * Fairfax, Indiana * Fa ...

* Greenbrae * Inverness Park *

Inverness Inverness (; from the gd, Inbhir Nis , meaning "Mouth of the River Ness"; sco, Innerness) is a city in the Scottish Highlands. It is the administrative centre for The Highland Council and is regarded as the capital of the Highlands. Histo ...

* Kentfield * Lagunitas-Forest Knolls * Larkspur * Lucas Valley-Marinwood * Manor * Marconi * Marin City * Marshall * McNears Beach *

Mill Valley Mill Valley is a city in Marin County, California, Marin County, California, United States, located about north of San Francisco via the Golden Gate Bridge and from Napa Valley. The population was 14,231 at the 2020 United States Census, 2020 ...

Muir Beach Muir Beach is a census designated place (CDP), unincorporated community, and beach on the Pacific Ocean. The community is located northwest of San Francisco in western Marin County, California, United States. Unlike many other entities in the ar ...

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 ...

* Novato * Olema * Paradise Cay * Point Reyes Station * Ross * San Anselmo * San Geronimo *

San Quentin San Quentin State Prison (SQ) is a California Department of Corrections and Rehabilitation state prison for men, located north of San Francisco in the unincorporated place of San Quentin in Marin County. Opened in July 1852, San Quentin is th ...

San Rafael San Rafael may refer to: Places Argentina * San Rafael, Mendoza * San Rafael Department, Mendoza Bolivia * San Rafael de Velasco, capital of San Rafael Municipality * San Rafael Municipality, Santa Cruz Chile * San Rafael, Chile, Maule ...

* Santa Venetia *

Sausalito Sausalito (Spanish language, Spanish for "small willow grove") is a city in Marin County, California, Marin County, California, United States, located southeast of Marin City, California, Marin City, south-southeast of San Rafael, California ...

* Sleepy Hollow * Stinson Beach *

Strawberry The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown hybrid species of the genus '' Fragaria'', collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely a ...

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 Tiburon (Spanish ''Tiburón'', " shark") may refer to: Places ;United States * Tiburon, California * Tiburón Golf Club Naples, Florida * Tiburon Peninsula (California), a peninsula in the San Francisco Bay Area of California ;Mexico * Tiburón ...

* Woodacre

San Mateo County

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