650 Area Code — San Mateo, CA
Area code 650 serves San Mateo and 4 other cities in California. Local time follows America/Los_Angeles. It has no overlay codes.
- State
- California
- Primary city
- San Mateo
- Timezone
- America/Los_Angeles
- In service since
- 1997
- Type
- Geographic
- Overlay codes
- None
Cities Served by 650
The 650 area code covers 5 cities and communities in California.
- San Mateo
- Palo Alto
- Redwood City
- Mountain View
- Daly City
About Area Code 650
Area code 650 is a North American Numbering Plan (NANP) area code that has been in service since 1997. It is administered by NANPA on behalf of the FCC and serves the California region anchored on San Mateo.
650 is currently a single-coverage geographic area code with no overlays. This means a 7-digit number in this area code is unique within its rate centers, though best-practice is always to dial the full 10-digit number when contacting a 650 line.
Mobile numbers in 650 are portable: a person who moved away from San Mateo may still carry a 650 mobile number on their device. If you receive an unexpected call from a 650 number, run it through the reverse lookup tool above for the most accurate, free identification.
If you live or do business in California, you may also interact with neighbouring or overlay codes. See the related codes section below to explore the rest of California.
Other California Area Codes
Continue exploring the California numbering plan.
650 Area Code FAQ
Where is area code 650?
Area code 650 is located in California, primarily serving San Mateo and surrounding cities including Palo Alto, Redwood City, Mountain View. The region operates on PT (America/Los_Angeles) time.
What state is 650 area code?
650 is a California area code. It was put into service in 1997 and has no overlay codes — it covers its geographic area exclusively.
Is 650 a scam area code?
650 is a legitimate North American area code allocated by NANPA to California. Like any geographic area code, scammers sometimes spoof 650 numbers — judge each call by content (urgent demands, unfamiliar transfers) rather than the area code alone. Run the specific number through our reverse lookup if you're unsure.
What time zone does 650 use?
Area code 650 operates on PT (America/Los_Angeles). Numbers in this area code follow standard California time-zone rules including any daylight-saving transitions for that region.
Can I look up a specific 650 phone number?
Yes. Use the reverse lookup widget above to enter a full 650 number. NumLocation returns the line type (mobile, landline, VoIP), carrier, rate-center city, and any public listings tied to the number — free.