Area codes in Alameda, California
Alameda, California uses 2 area codes — 510 and 341. The main Alameda area code is 510.
Area codes serving Alameda
Phone numbers in Alameda are written as ten digits — for example (510) 555-0190 — and fall in the Pacific Time zone.
How Alameda came to have 2 area codes
The original Alameda area code is 510, in service since 1991. As the area ran low on available numbers, an overlay code was added over the same region for new phone lines: 341 (2019). Existing numbers kept their original code — an overlay never forces anyone to change their number — which is why Alameda now uses all 2 codes and every local call is dialed with ten digits.
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Nearby cities
- Oakland area codes
- San Leandro area codes
- Berkeley area codes
- San Francisco area codes
- Daly City area codes
- Hayward area codes
- Walnut Creek area codes
- San Mateo area codes
More cities in California
- Los Angeles area codes
- San Diego area codes
- Sacramento area codes
- San Jose area codes
- Fresno area codes
- Long Beach area codes
- Bakersfield area codes
- Beverly Hills area codes
Frequently asked questions
What is the area code for Alameda?
The main area code for Alameda, California is 510. Alameda is now served by 2 area codes in total: 510, 341.
How many area codes does Alameda have?
Alameda has 2 area codes: 510, 341.
Why does Alameda have more than one area code?
As Alameda used up the numbers available in its original area code (510, in service since 1991), additional "overlay" codes were added over the same area so new phone numbers could keep being assigned.
How do you dial a Alameda number?
Dial all 10 digits — the area code (510 or 341) followed by the 7-digit local number. From abroad, dial +1, then the area code and number.
Sourced from the official NANPA (North American Numbering Plan Administrator) numbering database, current as of August 2, 2026. Refreshed monthly.