Alameda, California

Where Is Area Code 510?

Area code 510 serves the eastern side of San Francisco Bay in Northern California. It covers much of western Alameda County and part of western Contra Costa County. This area is part of the San Francisco Bay Area.

Major cities and communities in area code 510 include Oakland, Berkeley, Alameda, Fremont, Hayward, San Leandro, Union City, Newark, Richmond, El Cerrito, and San Pablo. Alameda County and Contra Costa County both use this code in different western sections. The code does not cover all of either county.

The region includes well-known Bay Area landmarks and features. Area code 510 reaches places along the East Bay shoreline, including the Port of Oakland and the Berkeley waterfront. It also serves communities near San Francisco Bay and the hills of the East Bay.

History of Area Code 510

Area code 510 began on September 2, 1991. It was created in a split from area code 415, which had covered San Francisco and much of the surrounding Bay Area. The split reflected fast telephone growth in the East Bay.

Area code 510 later lost part of its territory when area code 925 was created on March 14, 1998. That split moved many inland East Bay communities into 925, while 510 remained focused on the inner East Bay. Area code 341 was added as an overlay to 510 on July 22, 2019, which means both area codes now serve the same general area.

Key Facts About Area Code 510

• Area code 510 is in California, and Oakland is one of its best-known major cities.
• Area code 510 serves parts of Alameda County and Contra Costa County in the East Bay region of the San Francisco Bay Area.
• Area code 510 is in the Pacific Time Zone.
• Area code 510 was created on September 2, 1991, in a split from area code 415.
• Area code 925 split from 510 on March 14, 1998, removing many inland East Bay communities from 510.
• Area code 341 overlays area code 510, and the overlay started on July 22, 2019.
• Area code 510 includes the city of Berkeley, home to the University of California, Berkeley.
• Area code 510 covers important East Bay sites such as the Port of Oakland and shoreline communities along San Francisco Bay.

Frequently Asked Questions

What state is area code 510 in?

Area code 510 is in California.

What major cities use area code 510?

Major cities that use area code 510 include Oakland, Berkeley, Alameda, Fremont, Hayward, San Leandro, Union City, Newark, Richmond, El Cerrito, and San Pablo.

Is area code 510 a toll-free number?

No. Area code 510 is a geographic area code for parts of the East Bay in California.