Area code 925 is a
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 e ...
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, rea ...
that was split from
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 open s ...
in the U.S. state of
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, on March 14, 1998. It covers the inland portions of the East Bay counties of
Alameda
An alameda is a Avenue (landscape), street or path lined with trees () and may refer to:
Places Canada
*Alameda, Saskatchewan, town in Saskatchewan
**Grant Devine Dam, formerly ''Alameda Dam'', a dam and reservoir in southern Saskatchewan
Chile
...
and
Contra Costa in the northern area of California.
The area was originally part of
area code 415
Area codes 415 and 628 are telephone area codes in the North American Numbering Plan (NANP) for the city of San Francisco and its northern suburbs in Marin County (across the Golden Gate), and the northeast corner of San Mateo County in the U.S. ...
, one of the first three area codes created in California in 1947, which originally covered all of central California. In 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 open s ...
was created to encompass most of 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 ...
. Area code 925 was created March 14, 1998, when area code 510 was split along the natural border of the
Berkeley Hills
The Berkeley Hills are a range of the Pacific Coast Ranges that overlook the northeast side of the valley that encompasses San Francisco Bay. They were previously called the "Contra Costa Range/Hills" (from the original Spanish ''Sierra de la C ...
.
The area code includes southeastern Alameda County (Dublin, Pleasanton, Livermore, Sunol, and unincorporated areas surrounding those communities), and all of Contra Costa County except the western part (El Cerrito to Crockett).
Prior to October 2021, area code 925 had telephone numbers assigned for the
central office code
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 ...
988. In 2020, ''988'' was designated nationwide as a dialing code for the
National Suicide Prevention Lifeline
The 988 Suicide & Crisis Lifeline (formerly known as the National Suicide Prevention Lifeline) is a United States-based suicide prevention
Suicide prevention is a collection of efforts to reduce the risk of suicide. Suicide is often preven ...
, which created a conflict for exchanges that permit
seven-digit dialing
Seven-digit dialing is a telephone dialing procedure customary in some territories of the North American Numbering Plan (NANP) for dialing telephone numbers in the same numbering plan area (NPA). NANP telephone numbers consist of ten digits, of wh ...
. The area code was therefore transitioned to
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 ...
on October 24, 2021.
Cities in the 925 area code
Alameda County
*
Altamont
*
Dougherty
*
Dublin
Dublin (; , or ) is the capital and largest city of Republic of Ireland, Ireland. On a bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, bordered on the south by the Dublin Mountains, a part of th ...
*
East Pleasanton
*
Kilkare Woods
*
Livermore
*
Pleasanton
*
San Ramon Village
*
Sunol
*
Ulmar
Contra Costa County
*
Alamo
The Battle of the Alamo (February 23 – March 6, 1836) was a pivotal event in the Texas Revolution. Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna reclaimed the Alamo Mission near San Ant ...
*
Alamo Oaks
*
Antioch
Antioch on the Orontes (; grc-gre, Ἀντιόχεια ἡ ἐπὶ Ὀρόντου, ''Antiókheia hē epì Oróntou'', Learned ; also Syrian Antioch) grc-koi, Ἀντιόχεια ἡ ἐπὶ Ὀρόντου; or Ἀντιόχεια ἡ ἐπ ...
*
Bay Point
*
Bethel Island
*
Bixler
*
Blackhawk Black Hawk and Blackhawk may refer to:
Animals
* Black Hawk (horse), a Morgan horse that lived from 1833 to 1856
* Common black hawk, ''Buteogallus anthracinus''
* Cuban black hawk, ''Buteogallus gundlachii''
* Great black hawk, ''Buteogallus uru ...
*
Blackhawk-Camino Tassajara
Blackhawk-Camino Tassajara is a former census-designated place (CDP) in Contra Costa County, California, near the town of Danville. The unincorporated area consisted of the Blackhawk planned community and the surrounding Camino Tassajara area. A ...
*
Brentwood
*
Byron
George Gordon Byron, 6th Baron Byron (22 January 1788 – 19 April 1824), known simply as Lord Byron, was an English romantic poet and Peerage of the United Kingdom, peer. He was one of the leading figures of the Romantic movement, and h ...
*
Canyon
A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...
*
Clayton
*
Clyde Clyde may refer to:
People
* Clyde (given name)
* Clyde (surname)
Places
For townships see also Clyde Township
Australia
* Clyde, New South Wales
* Clyde, Victoria
* Clyde River, New South Wales
Canada
* Clyde, Alberta
* Clyde, Ontario, a tow ...
*
Concord
Concord may refer to:
Meaning "agreement"
* Pact or treaty, frequently between nations (indicating a condition of harmony)
* Harmony, in music
* Agreement (linguistics), a change in the form of a word depending on grammatical features of other ...
*
Danville
*
Diablo
*
Discovery Bay
Discovery Bay (DB) is a resort town on Lantau Island, Hong Kong. It consists of mixed, primarily residential, development, in particular upmarket residential development and private and public recreational facilities, including garden houses, ...
*
Knightsen
*
Lafayette
Lafayette or La Fayette may refer to:
People
* Lafayette (name), a list of people with the surname Lafayette or La Fayette or the given name Lafayette
* House of La Fayette, a French noble family
** Gilbert du Motier, Marquis de Lafayette (1757 ...
*
Marsh Creek Springs
*
Martinez
*
Mococo
*
Moraga
Moraga is a List of municipalities in California, town in Contra Costa County, California, Contra Costa County, California, in the San Francisco Bay Area. The town is named in honor of Joaquín Moraga, member of the famed Californio family. As ...
*
Norris Canyon
*
Oakley
*
Orinda
*
Orwood
*
Pacheco
Pacheco is a Portuguese and Spanish name which may refer to:
General
* Alex Pacheco (born 1958), animal rights activist, co-founder of PETA.
*Ángel Pacheco (general) (1793-1869), was an Argentine military officer trained by José de San Martín ...
*
Pittsburg
*
Pleasant Hill
*
San Ramon
*
Saranap
*
Shore Acres
*
Vine Hill
*
Waldon
*
Walnut Creek
A walnut is the edible seed of a drupe of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, ''Juglans regia''.
Although culinarily considered a "nut" and used as such, it is not a true bo ...
See also
*
List of California area codes
This is a list of area codes in California with service territory and installation dates.
* 209 – Stockton, Modesto, Merced, Turlock; the northern San Joaquin Valley and the central Sierra Nevada range. (Split from 415 on October 26, 1957; s ...
References
External links
Report on the 925 area codeproduced by the
California Public Utilities Commission
The California Public Utilities Commission (CPUC or PUC) is a regulatory agency that regulates privately owned public utilities in the state of California, including electric power, telecommunications, natural gas and water companies. In additi ...
, Telecommunications Division
List of exchanges from AreaCodeDownload.com, 925 Area Code
{{coord, 37.9, -122, region:US-CA, display=title
925
Alameda County, California
Contra Costa County, California
925
Northern California