The 357 overlay could be coming to the 559 area code by September 2025. Photo by Mike Meyers on unsplash.com

A new area code will be making its way to Central California, according to a news release Wednesday from the California Public Utilities Commission.

The new trio of digits will meet the demand in the region served by the 559 area code within a couple of years.

The second area code, called an overlay, will provide additional numbering options within the 559 region, which is expected to run out of available 3-digit prefix numbers (the first three numbers following the area code) by September 2025.

On Dec. 14, the commission approved the request from the third-party North American Numbering Plan Administrator to provide additional numbers with minimal customer inconvenience.

The change differs from the 1998 introduction of the 559 area code, which came in the form of a geographic split of the 209 area code which covers northern Central Valley counties including Merced, San Joaquin, Stanislaus and Sacramento. The 209 also covers small portions of Fresno and Madera counties.

Existing 559/357 customers will retain both their area code and specific telephone numbers. Call prices will not change due to the overlay and customers can still dial three-digit service numbers including 911.

The commission included several tips to prepare for the area code overlay:

• Contact security and/or alarm vendors to update dial-up numbers
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• Reprogram equipment including automatic dial, speed-dial and call forwarding, as well as modems for computers or internet dial-up access
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• Update stationary items to reflect the change
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• Provide area codes when sharing phone numbers and request area codes from those who share numbers with you
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• Remember previous area codes and the new area code will coexist within the same geographic region

 

The decision can be viewed here.

Documents relating to the proceeding can be viewed here. More information is available by visiting the commission’s website.