Area codes in Hayward, California
Hayward, California uses 2 area codes — 510 and 341. The main Hayward area code is 510.
Area codes serving Hayward
Phone numbers in Hayward are written as ten digits — for example (510) 555-0190 — and fall in the Pacific Time zone.
How Hayward came to have 2 area codes
The original Hayward 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 Hayward now uses all 2 codes and every local call is dialed with ten digits.
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Nearby cities
- Union City area codes
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- Oakland area codes
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More cities in California
- Los Angeles area codes
- San Diego area codes
- San Francisco area codes
- Sacramento area codes
- San Jose area codes
- Fresno area codes
- Long Beach area codes
- Bakersfield area codes
Frequently asked questions
What is the area code for Hayward?
The main area code for Hayward, California is 510. Hayward is now served by 2 area codes in total: 510, 341.
How many area codes does Hayward have?
Hayward has 2 area codes: 510, 341.
Why does Hayward have more than one area code?
As Hayward 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 Hayward 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.