The 628 area code is an overlay serving San Francisco and Marin County, California, layered over the iconic 415 code. Introduced in 2015 to supply new phone numbers, 628 covers the exact same territory as 415. If a 628 number has appeared on your caller ID, this guide explains where it comes from, how to dial it, and how to stay safe from spoofed calls.
Quick Summary: Area Code 628 at a Glance
| Detail | Information |
|---|---|
| Area Code | 628 |
| State | California (CA) |
| Major Cities | San Francisco, San Rafael, Novato, Sausalito |
| Time Zone | Pacific Time (PT) |
| Country Code | +1 (USA) |
| Overlay Codes | 415 (co-located) |
Geographic Coverage & Major Cities
Area code 628 covers the City and County of San Francisco along with all of Marin County, just across the Golden Gate Bridge. Because it is an overlay, it shares the identical footprint of the 415 area code rather than covering a separate zone.
Cities and communities served by the 628 area code include:
- San Francisco – one of the world’s most famous cities and a global tech and finance hub
- San Rafael & Novato – the largest cities in Marin County
- Sausalito, Mill Valley & Tiburon – scenic Marin communities on the bay
- Larkspur & Corte Madera – established Marin suburbs
As a newer code over one of the most prestigious phone regions in the country, 628 numbers are typically assigned to residents and businesses who obtained phone service after the original 415 numbers grew scarce.
A Brief History of Area Code 628
Area code 628 was activated in 2015 as an all-services overlay on the 415 region. The 415 code is one of the original area codes from 1947; over the decades it gave up the East Bay to 510 in 1991 and the Peninsula to 650 in 1997, leaving San Francisco and Marin. An overlay adds a second area code across the same geographic area, so existing 415 customers kept their numbers while new lines could be assigned either 415 or 628. The region has used mandatory 10-digit dialing ever since.
Time Zone & Best Time to Call
Numbers in the 628 area code use Pacific Time (PT). The region observes Daylight Saving Time, shifting from PST (UTC-8) to PDT (UTC-7) between March and November each year.
How to Dial Phone Numbers in Area Code 628
Because 628 is an overlay of 415, San Francisco and Marin require 10-digit dialing on every call.
Calling within the United States or Canada
- 10-digit dialing: Always include the area code – 628-XXX-XXXX.
- 11-digit dialing: You can also dial 1-628-XXX-XXXX; the leading 1 is the NANP country code.
Calling from outside the United States
- Format: [exit code] + 1 + 628 + XXX + XXXX
- From the UK, Europe, or most of Asia/Africa: 00 1 628 XXX XXXX
- From any mobile phone worldwide: +1 628 XXX XXXX
Is Area Code 628 a Scam? Safety & Protection Tips
Area code 628 is a legitimate California area code – a call from it is not fraudulent by default. However, scammers frequently spoof local codes like 628, faking the caller ID so their number appears to come from a trusted San Francisco line. Neighbor spoofing, which mimics the first six digits of your own number, is especially common.
Common scam tactics linked to this region
| Scam type | What to watch for |
|---|---|
| Government impersonation | Callers posing as the IRS or SSA threatening arrest or fines |
| Bank & card fraud alerts | Claims of “suspicious activity” seeking your account details |
| Tech support & crypto scams | Fake “IT department” calls or bogus cryptocurrency investment offers |
| Package delivery scams | Fake texts or calls about a “failed delivery” with a bad link |
How to report, block, and look up 628 callers
- Never share personal or financial details with an unexpected caller, however urgent they sound.
- Block the number using your phone’s built-in call-blocking feature or a reputable call-screening app.
- Look up the number with a trusted reverse phone lookup before returning any call.
- Report it to the FTC at reportfraud.ftc.gov and register at DoNotCall.gov.
Nearby & Related Area Codes in California
Area code 628 sits alongside several other Bay Area codes:
- 415 – the original San Francisco and Marin code that 628 overlays (see our 415 area code guide)
- 510 & 341 – the East Bay across the bay (see our 510 area code guide)
- 650 – the San Francisco Peninsula to the south (see our 650 area code guide)
- 707 & 369 – the North Bay and Wine Country (see our 707 area code guide)
Explore more codes across the state on our California area codes hub, or browse every prefix in our US area codes directory.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border California:
Frequently Asked Questions About Area Code 628
Where is the 628 area code located?
Area code 628 covers San Francisco and Marin County in California, including San Rafael, Novato, and Sausalito. It operates on Pacific Time as an overlay of area code 415.
What is the difference between 628 and 415?
There is no geographic difference. 628 is an overlay covering the exact same area as 415; it was added simply to supply more phone numbers as demand grew.
Is 628 a landline or cell phone area code?
Both. Area code 628 serves landlines, mobile phones, and VoIP numbers throughout San Francisco and Marin County.
Should I answer a call from an unknown 628 number?
If you are not expecting the call, let it go to voicemail. Legitimate callers leave a message, while spoofed or robocall numbers usually will not. Verify any unfamiliar number with a reverse lookup before calling back.
Related 628 Guides
- Is a 628 call safe? Read Is area code 628 a scam? Spam & safety guide.
- Local coverage: see the San Francisco area code guide.
- Worried about spam or robocalls? Browse our Scam Alerts directory.