Palo Alto, CA Area Code

Area code serving Palo Alto

Palo Alto sits in California, part of the West region and the Pacific Time zone. Its area code is 650, which covers San Francisco Peninsula, from Daly City through San Mateo County to Palo Alto. 650 has no overlay today, so every Palo Alto landline and mobile number with a local code starts with 650.

650 has served the area since 1997. If the region runs low on numbers, regulators will most likely add an overlay code on top rather than split the area, which would make 10-digit dialing mandatory.

Code	Area served	In service
650	San Francisco Peninsula, from Daly City through San Mateo County to Palo Alto	August 2, 1997

Nearby cities sharing this area code

• San Mateo
• Daly City
• Redwood City
• Mountain View
• South San Francisco
• San Bruno
• Menlo Park
• Burlingame
• Foster City
• Pacifica
• Half Moon Bay
• Los Altos
• Belmont

Getting a Palo Alto phone number

Any new landline, mobile or VoIP number from a local carrier in Palo Alto gets the 650 area code. Numbers come from the blocks each carrier holds in the area; a number ported in from elsewhere keeps its original area code, so you may also see out-of-state codes locally.

Dialing in Palo Alto

Palo Alto is covered by the single area code 650 with no overlay, so some local calls may still connect with seven digits. Dialing all 10 digits (area code + seven-digit number) always works and is the safest habit. From outside the US, dial +1, then the area code and number. See 10-digit dialing and overlay area codes for the background. For every code in California, visit the California area codes page.