925 Phone Number Lookup | California Area Code

Look up any phone number starting with 925 to identify the owner name, address, spam reports, and more. The 925 area code is a telephone area code serving a northern part of the U.S. state of California.

Look Up a 925 Phone Number

Enter a full 10-digit number to identify the caller and whether it has been reported as spam.

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Where Is Area Code 925 Located?

The numbering plan area 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).

Counties Served:

  • Alameda County
  • Contra Costa County

Major Cities:

Other Cities and Towns:

  • Alameda: Altamont
  • Alameda: Dougherty
  • Alameda: East Pleasanton
  • Alameda: Kilkare Woods
  • Alameda: Pleasanton
  • Alameda: San Ramon Village
  • Alameda: Sunol
  • Alameda: Ulmar
  • Contra Costa: Alamo Oaks
  • Contra Costa: Bay Point
  • Contra Costa: Bethel Island
  • Contra Costa: Bixler
  • Contra Costa: Blackhawk
  • Contra Costa: Byron
  • Contra Costa: Camino Tassajara
  • Contra Costa: Canyon
  • Contra Costa: Clyde
  • Contra Costa: Contra Costa Centre
  • Contra Costa: Diablo
  • Contra Costa: Discovery Bay
  • Contra Costa: Knightsen
  • Contra Costa: Marsh Creek Springs
  • Contra Costa: Mococo
  • Contra Costa: Moraga
  • Contra Costa: Norris Canyon
  • Contra Costa: Oakley
  • Contra Costa: Orinda
  • Contra Costa: Orwood
  • Contra Costa: Pacheco
  • Contra Costa: Pittsburg
  • Contra Costa: Pleasant Hill
  • Contra Costa: San Ramon
  • Contra Costa: Saranap
  • Contra Costa: Shore Acres
  • Contra Costa: Vine Hill
  • Contra Costa: Walnut Creek

Area Code 925 Location Map

Area Code 925 Location on California Map

Area code 925 is a general purpose code which was placed in service on March 14, 1998.

Phone Number Prefixes and Carriers

Our California phone number lookup for the 925 area code analyzes the three-digit prefix to identify the initially assigned telecommunications company and rate center. This prefix code data may help to determine the U.S. carrier, California geographic region, and local calling area associated with the phone number.

Phone numbers follow the following structure under the North American Numbering Plan:

  • NPA- area code (where the number was originally assigned)
  • NXX - Central office code that locates the specific neighborhood and identifies the service provider
  • XXXX - Subscriber number identifies the individual phone line within that local exchange

Understanding the area code can help you determine if a call is local to your area. However, keep in mind that due to mobile number portability and VoIP services, the caller may be anywhere in the United States, so it’s best to search for the most recent phone number details.

Prefixes by Company

Company Number of Prefixes
PACIFIC BELL 199
NEW CINGULAR WIRELESS PCS, LLC 39
SPRINT SPECTRUM, L.P. 32
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 26
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 25
LEVEL 3 COMMUNICATIONS, LLC - CA 24
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 16
TELEPORT COMMUNICATIONS AMERICA, LLC - CA 15
T-MOBILE USA, INC. 12
XO CALIFORNIA, INC. 12
O1 COMMUNICATIONS, INC. - CA 10
LEVEL 3 TELECOM OF CALIFORNIA, LP - CA 9
MATRIX TELECOM, LLC. S/I/I TNCI - CA 9
BANDWIDTH.COM CLEC, LLC - CA 6
COMCAST IP PHONE, LLC 6
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 6
METROPCS, INC. 5
GLOBAL CROSSING LOCAL SERVICES, INC. - CA 4
AT&T - LOCAL 3
ONVOY, LLC - CA 3
PEERLESS NETWORK OF CALIFORNIA, LLC - CA 2
AT&T CORP. 1
GETGO COMMUNICATIONS LLC - CA 1
YMAX COMMUNICATIONS CORP. - CA 1

Carrier names have been updated from their original FCC assignments to reflect current companies following mergers, acquisitions, and rebranding. Updates were determined using AI-assisted research and may not be accurate or reflect up to date changes. This data is provided without warranties of accuracy or completeness.

Prefixes by Rate Center

Rate Center Number of Prefixes
WALNUT CRK 78
CONCORD 70
PLEASANTON 69
ANTIOCH 43
LIVERMORE 37
DUBLN-SNRM 35
BSHP RNCH 30
DANVILLE 28
ECONTRCOST 12
MARTINEZ 12
PITTSBURG 10
CLAYTON 9
LAFAYETTE 9
ORINDA 8
MORAGA 7
PSBG WEST 5
SUNOL 4

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