Area Code 341 – California
The phone area code for California is 341 (international format +1341). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 341
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of California
Overview of Area Code 341
Area code 341 is a geographic North American Numbering Plan Area (NPA) code assigned to the state of California. It was introduced as an overlay for the East Bay region of the San Francisco Bay Area, which was previously served by area code 510. The overlay was implemented to address the exhaustion of available telephone numbers in the 510 area. As an overlay, 341 does not require a change to existing numbers; instead, it provides additional numbering capacity for new services in the same geographic region.
Geographic Coverage and Jurisdiction
The 341 area code serves the western portion of Alameda County and a small part of Contra Costa County, encompassing cities such as Oakland, Berkeley, Fremont, Hayward, Richmond, and San Leandro. This region is part of the San Francisco–Oakland–Berkeley metropolitan area and is characterized by a mix of urban, suburban, and industrial zones. The California Public Utilities Commission (CPUC) oversees telecommunications regulation in this area, ensuring compliance with state and federal guidelines.
Dialing Formats and Caller Instructions
For local calls within the 341/510 overlay area, callers must dial the full 10-digit telephone number (area code + 7-digit local number) even for calls to adjacent numbers. This is a mandatory requirement for all overlay areas in the United States. For international callers, the dialing format is +1 341 XXX XXXX, where +1 is the country code for the United States. For example, to call a business in Oakland, an international caller would dial +1 341 555 0123. Domestic callers from outside the 341/510 area should dial 1 341 XXX XXXX.
Numbering and Technical Considerations
Area code 341 is not assigned to any specific carrier; rather, numbers within this NPA are allocated to various telecommunications providers, including incumbent local exchange carriers (ILECs), competitive local exchange carriers (CLECs), and VoIP service providers. The overlay structure ensures that number portability is maintained, allowing customers to retain their numbers when switching providers. As with all North American numbering plan areas, the central office code (the next three digits) identifies the specific exchange, and the remaining four digits are the subscriber number.
Impact and Future Outlook
The introduction of 341 was part of a broader trend of overlay area codes in California, which helps to conserve numbering resources while minimizing disruption to existing customers. The CPUC projects that the 341/510 overlay will provide sufficient numbering capacity for several decades. As the region continues to grow, the overlay ensures that new residents and businesses can obtain telephone numbers without exhausting the supply.