🇺🇸 510 area code
Area code 510 covers Oakland, Fremont, Berkeley and Hayward and the surrounding area in California. It shares that territory with 341, so the same neighbourhood can have numbers in any of them. Enter a 510 number below for a free check before you call back.
- Location: Oakland, California
- Time zone: Pacific (UTC−8)
- In service since September 2, 1991
Consultar un número
Validez, operador, tipo de línea y región en la primera pasada.
Area code 510 at a glance
- Area code
- 510
- Location
- California, United States
- Main cities
- Oakland, Fremont, Berkeley, Hayward, Alameda, San Leandro
- Time zone
- Pacific (UTC−8)
- Local time now
- —
- In service since
- September 2, 1991
- Created from
- 415
- Overlay codes
- 341
- Codes split from it
- 341, 925
- Local calls
- Dial 1 + 10 digits
- Number format
- (510) 555-0123
- From abroad
- +1 510 555 0123
Cities in area code 510
- Oakland
- Fremont
- Berkeley
- Hayward
- Alameda
- San Leandro
- Union City
- Richmond
- Castro Valley
- Crockett
Is a 510 call a scam?
An area code tells you where a number was first assigned, not where the caller is. Mobile numbers keep their area code when people move, and internet (VoIP) numbers can be picked in any area code — so a 510 number can be calling from anywhere.
Robocallers exploit that with "neighbor spoofing": showing a 510 number to people in California because a local-looking call is more likely to be answered. If a 510 call claims to be your bank, the IRS or a delivery company, hang up and call the official number yourself.
About area code 510
510 entered service on September 2, 1991, when it was split from 415.
It is part of the 341/510 overlay: the codes cover the same area, and a new line there can be given a number in any of them. Two neighbours — or two phones in one household — can have different area codes. That is also why local calls need the full ten digits.
As the region grew, 341 and 925 were carved out of or added to 510.
Preguntas frecuentes
Area code 510 questions
Sources: NANPA NPA database (11/04/2026) and Google libphonenumber. Area codes show where a number was assigned, not where its owner is today.
Where is area code 510?
Area code 510 is in California, United States. It covers Oakland, Fremont, Berkeley, Hayward, Alameda and San Leandro.
What time zone is area code 510?
510 is in the Pacific (UTC−8) time zone, and observes daylight saving time.
What area codes overlay 510?
341 serves the same area as 510. Numbers in all of them are local to one another.
When did area code 510 start?
510 entered service on September 2, 1991, created from 415.
How do I find out who called me from 510?
Enter the full number in the lookup at the top of this page. The free check confirms whether the number is valid and shows its carrier, line type and region; a full report adds owner and public-web records where they are available.
Why am I getting calls from area code 510?
If you live in or near California, they may be genuinely local — or robocalls spoofing a local-looking number. Unknown 510 callers who will not leave a message are best looked up before you call back.
Got a call from 510?
Run the free check first — validity, carrier, line type and region — and unlock the full report only if you need it.