Antioch, California

Where Is Area Code 925?

Area code 925 is in Northern California. It serves much of the East Bay region, mainly in Contra Costa County and parts of Alameda County, east of the hills that separate the inner East Bay from inland suburbs.

Major cities in area code 925 include Antioch, Concord, Walnut Creek, Pleasanton, Livermore, Brentwood, Danville, Dublin, San Ramon, and Martinez. Communities such as Lafayette, Moraga, Orinda, Pittsburg, and Oakley also use 925.

This area includes the Diablo Valley, the Tri-Valley, and cities near the Sacramento-San Joaquin River Delta. Notable geographic features in the region include Mount Diablo and the Delta shoreline near Antioch and Pittsburg.

History of Area Code 925

Area code 925 began on March 14, 1998. It was created in a split from area code 510 as phone demand grew in the inland East Bay and nearby suburban communities.

Area code 925 has remained a separate geographic area code since that split. Public Utilities Commission records from California describe the change as part of the region's fast growth in population, housing, and telephone line use during the 1990s.

Key Facts About Area Code 925

• Area code 925 is in California, and Antioch is one of its major cities.
• Area code 925 serves communities in the Pacific Time Zone.
• Area code 925 was created on March 14, 1998, in a split from area code 510.
• Area code 925 is a geographic area code, not a toll-free code.
• Area code 925 covers much of Contra Costa County and parts of Alameda County in the East Bay.
• Major cities in area code 925 include Concord, Walnut Creek, Antioch, Pleasanton, Livermore, Brentwood, and San Ramon.
• Mount Diablo, a major East Bay landmark and state park, is within the 925 region.
• Los Medanos College in Pittsburg and Diablo Valley College in Pleasant Hill are located in the 925 calling area.

Frequently Asked Questions

What state is area code 925 in?

Area code 925 is in California.

What major cities use area code 925?

Major cities in area code 925 include Antioch, Concord, Walnut Creek, Pleasanton, Livermore, Brentwood, Danville, Dublin, San Ramon, Martinez, Pittsburg, and Oakley.

Is area code 925 a toll-free number?

No. Area code 925 is a geographic area code.