California · Pacific Time
Berkeley, CA Area Codes
Berkeley is served by 2 area codes (341, 510). Here's which is original, which are overlays, and how to pick one for a new local number.
Last updated October 3, 2026 · Source: NANPA
Area codes serving Berkeley
Berkeley sits in California, part of the West region and the Pacific Time zone. Its numbers are spread across an overlay of 2 codes that all cover the same ground: 341, 510.
The original code is 510 (in service since 1991). As the area ran low on numbers, regulators added overlay codes on top instead of splitting the city, so longtime residents kept their numbers while new lines received a newer code.
| Code | Area served | In service |
|---|---|---|
| 341 | Western Alameda and Contra Costa counties on the East Bay, including Oakland and Fremont | July 22, 2019 |
| 510 | Western Alameda and Contra Costa counties on the East Bay, including Oakland and Fremont | September 2, 1991 |
Nearby cities sharing these area codes
- Oakland
- Fremont
- Hayward
- Richmond
- San Leandro
- Alameda
- Union City
- Newark
- San Pablo
- El Cerrito
- Emeryville
- Albany
- Hercules
How to pick an area code for a new number
When you activate a new line in Berkeley, the carrier assigns whichever code has numbers available — you usually can't choose. If a specific code matters to you (for example the prestige of 510), ask the carrier whether any blocks remain, or request a number transfer. All codes here dial identically and cost the same.
Dialing in Berkeley
Because Berkeley is an overlay area, 10-digit dialing is mandatory: always dial the area code plus the seven-digit number, even for a neighbor. From outside the US, dial +1, then the area code and number. See 10-digit dialing and overlay area codes for the background. For every code in California, visit the California area codes page.
Quick answers
Berkeley area code FAQ
What area codes does Berkeley use?
Berkeley, CA is served by 2 area codes: 341, 510.
Which is the original Berkeley area code?
510 is the original code for Berkeley, in service since 1991; the others were added later for more numbers.
What time zone is Berkeley in?
Berkeley is in the Pacific Time zone.
Do I need to dial the area code in Berkeley?
Yes. With multiple overlapping codes, 10-digit dialing is required for every call in this area.