New Area Code to be Added to the 559 Area Code

The California Public Utilities Commission (CPUC) will begin the process to introduce a new area code to the area now served by the 559 area code, as the 559 area code is expected to be depleted of phone numbers by September 2025. The telecommunications service providers have proposed to introduce the new area code using the overlay method. Adding a new area code to the area now served by the 559 area code will provide additional prefixes and new telephone numbers for the 559 customers. The proposed overlay, pending CPUC approval, will allow all customers to keep their current phone numbers, including their area code.

The CPUC has made available a recorded webcast to inform the public about the new area code addition. Topics to be discussed in the recorded webcast include: (1) History of the 559 area code; (2) Area code relief process; (3) Area code relief methods; (4) Effects of the proposed overlay; and (5) Implementation timeline of the proposed overlay. The recorded webcast will be available to view and download at beginning April 4, 2023. Comments about the information presented in the webcast may be submitted to the CPUC Numbering Staff by e-mail at, or by postal mail to 505 Van Ness Ave., San Francisco, CA 94102 by May 4, 2023.