California (559/357) area code overlay

To ensure a continuing supply of telephone numbers, the new 357 area code will be added to the current 559 area code region. This is known as an area code overlay.

The overlay does not require you to change your existing area code or phone number.

Starting August 26, 2024, you should begin dialing 1+ area code + telephone number whenever you place a call. If you forget and dial just seven digits, your call will still be completed.

Effective February 26, 2025, you must dial 1+ area code + telephone number on all local calls. If you do not dial 1+ area code + telephone number, your calls will not complete and a recording will instruct you to hang up and dial again, including the area code.

Beginning March 26, 2025, new telephone lines or services may be assigned the new 357 area code. If you have a number in the new 357 area code, you must dial 1+ area code + telephone number or the call will not complete.

Download a copy of the bill insert in English or Spanish.