628 Area Code: 415 Overlay for San Francisco & Marin

628 · San Francisco

What is the area code for San Francisco?

The area code for San Francisco, California is 628, with overlay code 415 sharing the same geographic footprint. The 628 area code is a North American Numbering Plan geographic code assigned in 2015, covering the San Francisco and Marin County region. It serves approximately 1,000,000 residents on the Pacific Time (PT) (UTC-8 / UTC-7 DST).

The 628 area code has 192 assigned central-office prefixes (NXX codes, the three digits after the area code) across 14 rate centers, with numbers allocated to roughly 43 carriers.

At 192 of the ~792 usable central-office prefixes, the 628 area code has about 24% of its numbering capacity assigned, and that near-exhaustion is part of why overlay code 415 was added to the region. See how 628 compares in our NXX prefix allocation analysis across 338 US area codes. (Prefix data: localcallingguide.com / NANPA, 2026.)

Where is area code 628? Location and map area

Area code 628 is located in California, the United States. Its coverage area centers on San Francisco and spans the San Francisco and Marin County region. If you received a call from a 628 number, the caller's number was assigned in this area — though with number porting and virtual numbers, the person may be calling from anywhere.

The 628 location sits in Pacific Time (PT), so local business hours run roughly 9 a.m.–5 p.m. PT. Neighboring California area codes include 209, 213, 279.

For the full story — every city covered, overlay history, and local scam patterns — read the complete San Francisco area code guide.

All San Francisco area codes

San Francisco is served by 2 area codes across the metro area. 628 is the 2015 addition; the others were added as overlays or for surrounding suburbs.

• 415 — San Francisco — 1947 original
• 628 (current page) — Overlay on the same metro, assigned 2015

Cities served by the 628 area code

The 628 area code covers 3 major cities and towns across the San Francisco and Marin County region (CA):

Businesses across San Francisco and surrounding cities use 628 numbers to project local presence and lift call answer rates. Industry studies of local presence dialing consistently report answer-rate gains of 20–40% over toll-free or out-of-area numbers — a caller ID that matches the recipient's region looks familiar and gets picked up.

628 area code time zone and business hours

The 628 area code is in the Pacific Time (PT) zone (UTC-8 / UTC-7 DST). Standard business hours in 628 run 9 AM to 5 PM PT.

If you're calling into 628 from a different time zone, factor in the offset. For example, an Eastern Time business calling 628 at 9 AM ET reaches San Francisco at 6 AM PT — likely outside standard business hours.

History of the 628 area code

The 628 area code was introduced in 2015 when the North American Numbering Plan was first deployed. As San Francisco grew and number demand increased, overlay code 415 was added to serve the same geographic region — a common solution that avoids forcing existing subscribers to change their numbers.

• 1947 415 added to serve the same region
• 2015 628 entered service

Is the 628 area code safe? Spam and scam calls

628 is a legitimate geographic area code for San Francisco — it is not a scam code or a premium-rate prefix, and a call from a 628 number is most likely a genuine local caller. The risk is not the area code itself but a tactic called neighbor spoofing: scammers fake their caller ID so an unwanted call appears to come from your own area code, because people answer familiar numbers more readily.

If you get an unexpected 628 call, a few signals point to a likely scam — a pre-recorded message, urgent pressure to act now, a demand for payment by gift card or wire transfer, or anyone asking for passwords, Social Security, or account numbers. Let suspicious calls go to voicemail, never share personal information, and report fraud to the FTC at reportfraud.ftc.gov.

The FCC consumer guide on spoofing explains your rights under the Truth in Caller ID Act. A real San Francisco business will leave a clear voicemail and will not pressure you.

US carriers verify caller ID with the STIR/SHAKEN framework, which flags many spoofed numbers as "Spam Likely" before they ring. DialPhone 628 numbers are registered for STIR/SHAKEN attestation, so calls from your business are verified as genuine and reach customers without a false spam label. See the DialPhone guide to VoIP security for more.

Why get a 628 area code number for your business?

Getting a 628 number gives your business three measurable advantages over a toll-free or out-of-area number:

1. Local trust signal. Customers in San Francisco recognize 628 as their home area code. Caller ID matching builds immediate credibility for service businesses, sales outreach, and patient communication.
2. Higher answer rate. Calls from a familiar local area code are answered far more often than unknown or toll-free numbers — industry measurements of local presence dialing put the lift at 20–40%, which matters most for outbound sales, appointment confirmations, and time-sensitive service callbacks.
3. Targeted marketing. Businesses serving San Francisco and the broader San Francisco and Marin County can advertise a local number across print, radio, billboards, and digital channels for higher conversion than a national 800 number.

For businesses in San Francisco and surrounding cities, top industries that benefit from local 628 presence include Tech, Entertainment, and Healthcare. DialPhone's AI receptionist is available for every 628 number — never miss a call, even after standard business hours.

How to get a 628 area code number

Setting up a 628 business number with DialPhone takes under 10 minutes:

1. Sign up for a DialPhone plan. Choose any plan starting at $24/user/month. Free 14-day trial, no credit card required.
2. Search available 628 numbers. Filter the DialPhone number inventory by area code, city, or pattern.
3. Choose your number and configure. Assign your new 628 number to a user or team, set up call routing, voicemail, AI receptionist, and business SMS.
4. Port your existing number (optional). Already have a 628 number? Free number porting in 2 to 5 business days with zero service interruption.

New to local numbers? The complete guide to getting a local phone number covers choosing the right area code, porting an existing line, and avoiding spam flags.

628 area code overlay codes

The San Francisco and Marin County region is served by multiple overlay area codes:

Area Code	Coverage
628	Primary area code for San Francisco and Marin County, assigned 2015
415	Overlay — same geography (assigned 1947)

All overlay codes serve the same San Francisco region. New subscribers may be assigned any available code; existing numbers retain their original prefix.

AI receptionist for 628 area code businesses

Every DialPhone 628 number includes optional AI receptionist coverage, available 24/7. The AI handles calls when your team is unavailable — answering common questions, booking appointments, routing urgent callers to on-call staff, and capturing voicemail with full transcription and intent tagging.

For businesses in San Francisco that handle high call volume, run extended hours, or need bilingual support (especially valuable in multilingual metros like San Francisco), the AI receptionist reduces voicemail backlog and improves first-call resolution.

All area codes in California

California has 40 active geographic area codes. The 628 area code is part of the same numbering plan as the codes listed below — calls between them are typically local within the state, depending on the carrier.

Nearby area codes

Related area codes in California and the Pacific Time (PT) region:

• 209 area code — Stockton, California
• 213 area code — Los Angeles, California
• 279 area code — Sacramento, California
• 310 area code — Los Angeles, California
• 323 area code — Los Angeles, California
• 341 area code — Oakland, California

All California area codes → · Browse all US area codes →

More area codes: ← 626 Pasadena · 629 Nashville →

How this page is verified

DialPhone re-verifies every area code page every 90 days. Area code geography, timezone, and overlay data come from the official North American Numbering Plan Administration (NANPA) database. Pricing reflects the published DialPhone plan tiers — see the pricing page for current details. Number availability varies; check the DialPhone signup flow for live inventory in the 628 region.

What to know before getting a 628 number

• Number availability is finite. Popular San Francisco area codes can be inventory-constrained — request specific vanity patterns early.
• Porting timing varies. Most 628 ports complete in 2-5 business days; complex multi-line legacy contracts can take 7-10.
• HIPAA tier required for healthcare. The Core $24 plan doesn't include a BAA — healthcare users need Advanced ($34) or above.