Area code 510: California
What is area code 510?
Area code 510 is a US state area code for California, on Pacific Time. It has 785 prefixes in service across 13 rate centers, the largest being Oakland:Main-Piedmont Da, Hayward and Fremont-Newark:Main Da. It shares its area with 341, so local numbers there can start with any of them. Local calls there take 1 + 10 digits.
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See the phone add-onArea code 510 facts
| Location | California, United States |
|---|---|
| Time zone | Pacific Time |
| Overlays | 341 |
| Split from | 415 |
| In service since | September 2, 1991 |
| Local calls | 1 + 10 digits |
| Carrier | Not shown. An area code is where a number was issued; numbers port between carriers. Check line type |
In short: 510 is California (Pacific Time). Format checks here are free and run in your browser; the current carrier and line type need a live lookup. Bulk phone number validator · Pro + Phone plan
Local time in area code 510
America/Los_Angeles
Prefixes in service
785 of 792 possible
13 rate centers
Which cities and towns use area code 510?
NANPA records each prefix against a rate center, the local billing area a number belongs to, usually named after its main town. These are the 510 rate centers with the most prefixes in service. 1 smaller ones aren't listed.
| Rate center | Prefixes |
|---|---|
| Oakland:Main-Piedmont Da | 204 |
| Hayward | 117 |
| Fremont-Newark:Main Da | 81 |
| Oakland:Berkeley Da | 70 |
| Oakland:Trinidad Da | 60 |
| Richmond | 53 |
| Fremont-Newark:Oliver Da | 45 |
| Oakland:Alameda Da | 42 |
| Oakland:Fruitvale Da | 39 |
| El Sobrante-Pinole | 28 |
| Fremont-Newark:Greenleaf Da | 25 |
| Hercules-Rodeo | 14 |
Source: NANPA central office code assignments, file dated 10/17/2026. Each prefix holds up to 10,000 numbers.
How do I dial a 510 number?
NANPA's dialling plan for 510: local calls inside the code take 1 + 10 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.
| Local call inside 510 | 1-510-555-0147 |
|---|---|
| From another US or Canadian area code | 1-510-555-0147 |
| From outside North America | +1 510 555 0147 |
| E.164, for CRMs and SMS tools | +15105550147 |
When did area code 510 start?
Area code 510 went into service on September 2, 1991, split from 415. Today 510 and 341 cover the same area as an overlay, which is why 10-digit dialling is needed for local calls there.
Tools for 510 numbers
- Bulk phone number validator
Format, country and number type for every number in a CSV, with E.164 output.
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- Area code time zone
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- NPA-NXX lookup
Rate center and state for one prefix, a level below the area code.
- TCPA calling hours checker
Whether it's inside the federal 8 a.m. to 9 p.m. calling window there now.
Next step
A 510 number tells you where it was issued, not what it is now.
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Area code 510 questions
- What state is area code 510?
- Area code 510 is in California, United States. Its largest rate centers by number of prefixes are Oakland:Main-Piedmont Da, Hayward, Fremont-Newark:Main Da, Oakland:Berkeley Da and Oakland:Trinidad Da.
- What time zone is area code 510 in?
- Pacific Time.
- What area codes overlay 510?
- 341. An overlay adds a new code to the same area instead of splitting it, so neighbours can have different area codes and local calls need 10 digits.
- When did area code 510 start?
- Area code 510 went into service on September 2, 1991, split from 415.
- Is a 510 number a cell phone or a landline?
- The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
- How many phone numbers does area code 510 have?
- 785 of its 792 possible prefixes are in service, and each prefix holds up to 10,000 numbers. That counts prefixes assigned to carriers, not numbers in use.
- Does a valid format mean a 510 number is in service?
- No. A format check only says the digits fit the North American Numbering Plan and that 510 is an assigned code. It cannot tell whether the number is connected, who answers it or which carrier serves it today, because numbers are reassigned and ported. A live carrier lookup reports the current carrier and line type, but even that is not proof someone answers.
- Can I check a list of 510 numbers for free?
- Yes. Paste them in the list tab above or upload a CSV to the bulk phone number validator: format, E.164, country and the numbering-plan line type are free for every row, with no account. Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month).
Other area codes in California
All California area codes on the area code index.
209213279310323341350357369408415424442530559562619626628650657661669707714738747760805818820831837840858909916925949951
Sources
Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and rate centers: NANPA central office code assignments, 10/17/2026. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.