Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — AREA-CODE/510

510 area code

Area code 510 is in California. It covers Oakland, Hayward, Richmond and 18 other places: 55 ZIP codes in Alameda and Contra Costa counties. Local time there is , Pacific Time. In service since 1991; 341 (2019) overlays it, so a number from there can have either code.

Time zone
Pacific
Largest city
Oakland
Overlays
341
In service since
1991
Rate centres
13
Prefixes assigned
785 (7,850,000 numbers)

Who calls from a 510 number

NANPA records the carrier each block of 510 numbers is assigned to. Of the 7.8 million 510 numbers assigned, 36% are with mobile carriers (T-Mobile, AT&T Mobility and Verizon Wireless); 31% with local phone companies (AT&T); 31% with cable, internet-calling, business and other carriers (Onvoy and Bandwidth); 2% with paging companies.

That is who the numbers were assigned to: people keep their number when they change carrier, so any one number may have moved since.

Carriers holding the most 510 numbers
CarrierKindShare
AT&TLandline31%
T-MobileMobile17%
AT&T MobilityMobile11%
OnvoyCable, VoIP, other9%
Verizon WirelessMobile8%
BandwidthCable, VoIP, other5%

An area code says where a number was issued, not where the caller is: people keep their numbers when they move, and caller ID can be set to show any number, which the FCC calls spoofing. If a call you did not expect asks for money or personal details, the FCC advises hanging up and calling the company back on a number you look up yourself. Unwanted calls can be reported to the FTC at ReportFraud.ftc.gov.

Places in area code 510

The 4 places with a telephone rate centre of their own using 510, largest first. Each links to its ZIP codes.

Places in area code 510
PlaceZIP codesPopulation
Oakland, CA 26 439,418
Hayward, CA 7 158,801
Richmond, CA 7 115,505
Crockett, CA 1 3,372

Nearby places using 510

These places have no rate centre of their own in NANPA's records; the nearest one uses 510. Near an area-code boundary that can be wrong for part of a town.

ZIP codes in area code 510

55 ZIP codes in 13 towns, by the town each is mailed to, largest first. Each links to its own page.

Where 510 numbers are issued

NANPA's rate centres with the most 510 prefixes (each prefix is 10,000 numbers), under NANPA's own abbreviated names.

Rate centres using area code 510
Rate centrePlacePrefixes
OKLD MN-PD Oakland 204
HAYWARD Hayward 117
FRNK MAIN — 81
OKLD BKLY Oakland 70
OKLD TRNID Oakland 60
RICHMOND Richmond 53

Counties

The counties of its ZIP codes, most residents first, with how many of its ZIP codes each has.

Which code covers where you are now? What area code am I in? answers from your location.

Questions about area code 510

Where is area code 510?

Area code 510 is in California. It covers Oakland, Hayward, Richmond and 18 other places: 55 ZIP codes in Alameda and Contra Costa counties.

What ZIP codes are in area code 510?

55 ZIP codes, by the town each is mailed to: Oakland (26, 94601 to 94666), Hayward (7, 94540 to 94557), Richmond (7, 94801 to 94850), San Leandro (3, 94577 to 94579) and 9 more towns. The full list is on this page.

What time zone is area code 510 in?

Pacific time.

Is a 510 number a mobile or a landline?

It can be either. 36% of 510 numbers are assigned to mobile carriers and 31% to local phone companies (NANPA, 2026-10-10); the rest are with cable, internet-calling, business and paging carriers. A number keeps its area code when it moves to another carrier.

What area codes overlay 510?

341. They cover the same area as 510, so a new number there can be given any of them.

Does a 510 number mean the caller is in California?

Not necessarily. An area code says where the number was first issued. People keep their numbers when they move or switch carriers, and calling software can show any number, so a 510 call can come from anywhere.

Other area codes in California

All 41 California area codes, by area, with the cities each covers

Source: NANPA NPA database, central office code and thousands-block assignments, 2026-10-10. Places are matched to NANPA's rate centres by name; see sources.

Cite this page

zipcodes.pro. “Area code 510.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/area-code/510

Underlying data is public domain or openly licensed — sources, vintages and licences.