Towns and cities in the San Francisco Bay Area currently using area code 510 will be served by a new code: 341 is the new NPA announced by the California Public Utilities Commission in June. The two area codes will overlay or cover the same area. Some of the cities served by the new overlay complex: Alameda, Berkeley, El Cerrito, Oakland… 1+10 digit dialing becomes the new calling method starting June 22, 2019.
- December 15, 2018 – permissive 7/1+10 digit dialing begins (local calls within Numbering Plan Area 510 may be dialed using either 7 or 1+10 digits)
- June 22, 2019 – mandatory 1+10 digit dialing begins – all calls within NPA 510 must be dialed using 1+10 digits
- July 22, 2019 – area code 341 enters service
See official announcement and map of the new overlay complex 510/341 (PDF document)