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 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 ...

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 ...

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 ...

, on March 14, 1998. It covers the inland portions of the East Bay counties of

Alameda An alameda is a 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 * Alameda (Santiago ...

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. s ...

, one of the first three area codes created in California in 1947, which originally covered all of central California. In 1991,

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 calli ...

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 network of over 200+ crisis centers that provides 24/7 service via a toll-free hotline with the number 9- ...

, 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 ...

. 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 Ireland. On a bay at the mouth of the River Liffey, it is in the province of Leinster, bordered on the south by the Dublin Mountains, a part of the Wicklow Mountains range. At the 2016 ...

* 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 An ...

* 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 Bethel Island is an island in the Sacramento–San Joaquin River Delta of Contra Costa County, California, approximately east of Antioch. The island describes itself as "the heart of the California Delta." Bethel Island (formerly known as Be ...

* Bixler * Blackhawk *

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. ...

* 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 peer. He was one of the leading figures of the Romantic movement, and has been regarded as among the ...

Canyon A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency to cut ...

* Clayton * Clyde *

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 *

Marsh Creek Springs Marsh Creek Springs was a private recreational facility in Contra Costa County ) of the San Francisco Bay , subdivision_type = Country , subdivision_name = United States , subdivision_type1 = State ...

* Martinez * Mococo *

Moraga Moraga is a town in 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 of 2020, Moraga had a total population of 16,870 people. Moraga ...

* Norris Canyon *

Oakley Oakley may refer to: Places Antarctica *Oakley Glacier United Kingdom * Oakley, Bedfordshire, England *Oakley, Buckinghamshire, England *Oakley, Dorset, England *Oakley, Fife, Scotland * Oakley, Gloucestershire, England * Oakley, Hampshire, En ...

Orinda Orinda is a city in Contra Costa County, California, United States. The city's population as of the 2020 census is estimated at 19,514 residents. History Orinda is located within four Mexican land grants: Rancho Laguna de los Palos Colorados, ...

* Orwood * Pacheco * Pittsburg * Pleasant Hill * San Ramon *

Saranap Saranap (until 1913, Dewing Park) is a residential census-designated place (CDP) within central Contra Costa County, California. Lying at an elevation of 180 feet (55 m), it is bounded on the south and east by portions of Walnut Creek (including th ...

* Shore Acres * Vine Hill *

Waldon Waldon is a surname. Notable people with the surname include: *Alton Waldon (born 1936), American politician * Billy Ray Waldon (born 1952), American murderer *Connor Waldon (born 1995), English footballer *Keith Waldon, English football manager S ...

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 ...

References

External links

Report on the 925 area code
produced 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 addi ...

, Telecommunications Division
List of exchanges from AreaCodeDownload.com, 925 Area Code
{{coord, 37.9, -122, region:US-CA, display=title

925 Year 925 ( CMXXV) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire * May 15 – Nicholas I Mystikos, twice the Ecumenical Patriarch of Constant ...

Alameda County, California Contra Costa County, California

Northern California

Cities in the 925 area code

Alameda County

Contra Costa County

See also

References

External links