Area Code 707 – California
The phone area code for California is 707 (international format +1707). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 707
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of California
Geographic Coverage and Administrative Jurisdiction
Area code 707 is a geographic North American Numbering Plan (NANP) code serving a substantial portion of Northern California, excluding the immediate San Francisco Bay Area. It encompasses a diverse region stretching from the Pacific Coast to the inland valleys, including the counties of Sonoma, Napa, Mendocino, Lake, Humboldt, and Del Norte, as well as parts of Solano and Marin counties. Major cities within the 707 calling area include Santa Rosa, Petaluma, Napa, Vallejo, Eureka, and Ukiah. The region is known for its wine country, redwood forests, and coastal communities.
Dialing Formats and Caller Instructions
For local callers within the 707 area code, standard 10-digit dialing (area code + 7-digit subscriber number) is required, as mandated by the California Public Utilities Commission. For example, to call a landline in Santa Rosa, a local caller would dial 707-555-0123. International callers must dial the United States country code, followed by the area code and subscriber number: +1 707 555 0123. For calls from other NANP countries (e.g., Canada), dial 1 707 555 0123.
Overlay and Numbering Resources
Currently, area code 707 does not have an overlay code, meaning it is the sole area code serving this geographic region. However, due to projected number exhaustion, an overlay code (369) has been assigned and is planned to be introduced in the near future. Once implemented, 10-digit dialing will remain mandatory, and callers may need to dial the new code for new numbers. This overlay will not require changes to existing numbers.
Technical and Regulatory Notes
As a geographic code, 707 is assigned to local exchange carriers and competitive providers, serving both wireline and VoIP services. Number portability allows customers to retain their 707 numbers when switching providers, even if they move outside the geographic area, subject to FCC regulations. The code is not reserved exclusively for mobile services; mobile numbers can have a 707 prefix, but they are non-geographic in nature and can be used anywhere.