Area code 650 covers San Mateo and surrounding areas in California. It was activated in 1997 as an overlay of area code 415. For the full picture, see all California area codes.
| State | California |
|---|---|
| Primary city | San Mateo |
| Cities also served | San Mateo, Palo Alto, Redwood City, Mountain View, South San Francisco, Menlo Park, Burlingame, Daly City |
| Time zone | Pacific (UTC-8 / UTC-7 DST) |
| Year established | August 2, 1997 |
| Original 1947 NPA? | No |
| Parent code | 415 |
| Overlay codes | None |
| Currently in use? | Yes, actively assigned |
| Ten-digit dialing required? | Yes |
History of Area Code 650
Area code 650 was activated on August 2, 1997 in connection with area code 415. The decision was driven by population growth and the exhaustion of available phone numbers in the original numbering plan area.
Since its activation, the geographic area covered by 650 has been reshaped by the following splits:
- 1997 — area code 650 split off to cover Area code 650 was split from 415 on August 2, 1997, assigning the San Francisco Peninsula — most of San Mateo County and the northwestern portion of Santa Clara County — its own code to relieve number exhaustion in 415.
Cities and Areas Served by 650
Area code 650 serves San Francisco Peninsula — most of San Mateo County and the northwestern portion of Santa Clara County, including the following cities and communities:
- San Mateo
- Palo Alto
- Redwood City
- Mountain View
- South San Francisco
- Menlo Park
- Burlingame
- Daly City
Nearby area codes covering the same broader region include: 415, 408, 510, 925, 831.
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Browse 650 Numbers →The Cultural Weight of a 650 Number
Area code 650 was carved out of the historic 415 code on August 2, 1997, as surging demand from fax machines, cellular phones, pagers, and early internet services threatened to exhaust 415’s numbering resources before the end of that year. The California Public Utilities Commission formally approved the new code on August 16, 1996, and NANPA issued planning guidance in November 1996 to coordinate the transition. The geographic split gave the San Francisco Peninsula — from Daly City and South San Francisco south through San Mateo County and into northwestern Santa Clara County, including Palo Alto, Mountain View, and Los Altos — its own dedicated numbering space. Ten-digit dialing became mandatory in the region by October 24, 2021, driven by the nationwide reservation of 988 as the mental-health crisis lifeline. As of early 2026, 650 remains a standalone code with no active overlay; NANPA projects number exhaustion around the third quarter of 2029.
The 650 code is synonymous with the Stanford-to-Sand Hill Road corridor at the heart of Silicon Valley. Stanford University’s Palo Alto campus, Google’s headquarters at 1600 Amphitheatre Parkway in Mountain View, and Meta’s campus in Menlo Park all carry 650 numbers, making the prefix a shorthand for venture-capital culture and the global technology industry. NASA Ames Research Center in Mountain View adds a legacy of aerospace and computing research to the code’s identity. The area’s median household income — San Mateo County’s is among the highest of any county in the United States — reflects the concentration of high-wage tech and biotech employment that defines the region served by 650.
How to Get a Phone Number with Area Code 650
There are three ways to get a phone number with the 650 area code, each suited to a different need:
- Buy from a premium-number specialist. Companies that hold curated inventories of specific area codes can sell you a 650 number directly, often with a one-time fee and ownership transferred to you (no recurring carrier fees). This is the option for picking a specific memorable number, or for getting an area code that most carriers won’t let you request. Browse our 650 inventory.
- Sign up with a VoIP carrier. Voice-over-IP services (such as Google Voice, OpenPhone, Grasshopper, and many others) can typically provision a 650 number on request, especially for active overlay codes. You won’t usually get to pick the specific number, but you’ll get a working line in the area code. This is the cheapest option for anyone who doesn’t need a particular number.
- Port an existing 650 number. If you already have a 650 phone number with another carrier, you can transfer it (port it) to a new service provider while keeping the number. This works for landlines, cell phones, and VoIP services, though landlines outside of California sometimes can’t accept inbound ports of 650 numbers due to 911 routing rules.
Looking for a 650 number? 212areacode.com offers premium 650 numbers for San Mateo, California — choose your number, port it to any carrier in 3–5 business days, and pay a one-time fee with no monthly charges. Browse available 650 numbers →
Frequently Asked Questions
Is the 650 area code still in use?
Yes. 650 is actively assigned to new phone lines in San Francisco Peninsula — most of San Mateo County and the northwestern portion of Santa Clara County.
What is the parent area code of 650?
Area code 650 is an overlay of 415. Both codes serve the same region of California.
Can I get a 650 number if I don't live in California?
Yes. Phone numbers are no longer tied to a physical address. With VoIP service or a number broker, you can hold a 650 number from anywhere in the world. The number routes to whatever device or carrier you specify.
Is 650 a scam area code?
No. 650 is a legitimate, active area code for San Francisco Peninsula — most of San Mateo County and the northwestern portion of Santa Clara County. Like any area code, scammers occasionally spoof 650 caller IDs, but the code itself is heavily used by real California businesses, government offices, and residents.
Does area code 650 have an overlay code?
No. As of 2026, area code 650 has no active overlay. The CPUC approved an overlay plan in 1999 but suspended it after number-conservation measures extended the code’s life. NANPA currently projects 650 will exhaust around Q3 2029, at which point an overlay would likely be implemented.
What cities are in area code 650?
Area code 650 covers most of San Mateo County and the northwestern corner of Santa Clara County. Key cities include San Mateo, Redwood City, Palo Alto, Mountain View, South San Francisco, Menlo Park, Burlingame, Daly City, San Bruno, Pacifica, Los Altos, and the Stanford University area.
Why was area code 650 created?
Rapid population growth, the spread of fax machines, pagers, and cellular phones, and the explosion of early internet services exhausted available numbers in the 415 code far faster than anticipated. The CPUC split the Peninsula and northern Santa Clara County into the new 650 code, effective August 2, 1997.
Do I need to dial ten digits for a 650 number?
Yes. Since October 24, 2021, all calls within area code 650 require 1 + ten-digit dialing. This change was mandated because 650 previously assigned numbers to the 988 central-office prefix, which conflicted with the nationwide 988 mental-health crisis line.
