__NOTOC__ In 1947, the

American Telephone and Telegraph Company AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to busi ...

(AT&T) devised the first nationwide

telephone numbering plan 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, reach ...

and assigned the

original North American area codes The original North American area codes were established by the American Telephone and Telegraph Company (AT&T) in 1947. The assignment was in accord with the design of a uniform nationwide telephone numbering plan that supported the goal of dialin ...

. The state of California was divided into three numbering plan areas (NPAs) with distinct area codes:

213 Year 213 ( CCXIII) was a common year starting on Friday of the Julian calendar. At the time (in Rome), it was known as the Year of the Consulship of Aurelius and Calvinus (or, less frequently, year 966 ''Ab urbe condita''). The denomination 213 ...

, 415, and

916 __NOTOC__ Year 916 ( CMXVI) was a leap year starting on Monday of the Julian calendar. Events By place Europe * Sicilian Berbers in Agrigento revolt and depose the independent Emir Ahmed ibn Khorob. They offer Sicily to the Fatimid C ...

, for the southern, central, and northern parts of the state, respectively. In 1949, Oakland, CA, received the fifth regional dial switching center 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 paved the way for Direct Distance Dialing (DDD) by telephone service subsc ...

in the nation, which set the stage for direct distance dialing by customers in the 1950s. In 1950, the boundaries of the California numbering plan areas 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 North Coast or Northcoast may refer to : Antigua and Barbuda * Major Division of North Coast, an urban area and major division in the parish of Saint John * North Coast, Barbuda, an administrative district of Barbuda Australia * New South Wa ...

to the

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

border, while 916 was redrawn to comprise the northeastern corner of the state. This realignment resulted in Sacramento changing from area code 415 to 916, and Bakersfield to 213. During the initial trials of DDD, starting in 1951,

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 assigned in 1957 in an area code split of the area code 504, 504 numbering plan ...

was temporarily installed for the new toll-switching center in San Francisco to separate calls destined through Oakland (415), as six-digit translation was not available until two years later. In subsequent decades the California numbering plan areas underwent many

area code split In telecommunications, an area code split is the practice of introducing a new telephone area code by geographically dividing an existing numbering plan area (NPA), and assigning area codes to the resulting divisions, but retaining the existing a ...

s and

area code overlay In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to the same geographic numbering plan area (NPA). Area code overlays are implemented in territories of the North American Numbe ...

arrangements. As of March 2025, California has 41 active area codes.

References

External links

{{DEFAULTSORT:List Of California Area Codes

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Area codes 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, reach ...

Subdivisions of California

See also

References

External links