650 area code — Palo Alto, CA geographic

Data: NANPA public reports, current as of July 28, 2026.

State
California
Major area
Palo Alto
Time zone
Pacific
In service since
1997-08-02
Split from
415
Active prefixes
707
Rate centers
15
Carriers
36
Projected exhaust
3Q 2039

Area code 650 is a geographic code serving Palo Alto, California in the Pacific time zone. It has been in service since August 2, 1997. Note that porting and VoIP mean a 650 number can be used from anywhere — the code marks where the number was assigned.

707 central-office prefixes are currently active in this code, spread across 36 code-holding carriers. Thousands-block pooling applies to 509 prefixes, so a single prefix can belong to several carriers. Its prefixes map to 15 distinct rate centers.

650 was created from 415 in 1997.

NANPA projects numbering capacity to exhaust in 3Q 2039.

Dialing: 1+10D locally, 1+10D to other codes.

Use this page to decode where 650 numbers come from — and remember that spoofing means the screen can lie about everything except your own caution.

Largest localities in 650

Largest rate centers in area code 650
Locality (rate center)Active prefixesAlso served by
Palo Alto 144
San Mateo 125
Mountain View 91
South San Francisco 88
Redwood City 64
San Carlos-belmont 43
Los Altos 28
Millbrae 24
San Francisco:juniper Da 22 415, 628
Half Moon Bay 20

FAQ

Where is a 650 number from?

650 is assigned to Palo Alto and surrounding areas of California in the Pacific time zone. The three digits after the area code (the prefix) narrow it down to a rate center.

Is 650 a toll-free number?

No. 650 is a geographic code; calls are billed like any other domestic call. Toll-free codes are 800, 833, 844, 855, 866, 877 and 888.

Will 650 run out of numbers?

NANPA's current forecast projects exhaust in 3Q 2039 — decades of capacity remain.