The 559 area code is expected to exhaust all available prefixes by September 2025. The CPUC’s action on Dec. 14, 2023, approves the request of the North American Numbering Plan Administrator, the neutral third-party area code relief planner for California, for an area code overlay to provide additional numbering resources to meet the demand for telephone numbers while minimizing customer inconvenience. The new area code to overlay the 559 area codes is 357.

No existing customers will be required to change their area code or specific telephone number. The new overlay area code of 357 will be available for new telephone number assignments in the same region as the 559 area code upon exhaust of available prefixes in the existing 559 area code.

On January 26, 2023, NANPA filed A.23-01-012 with the CPUC on behalf of the telecommunications industry, requesting that the CPUC approve an overlay in the 559 area code region to provide additional numbering resource.

Background

The 559 area code was introduced in 1998 when the CPUC approved a geographic split of the 209 area code, creating the 559 area code. The 559 area code is in central California in the San Joaquin Valley. The 559 area code includes all or portions of Fresno, Madera, Mariposa, Merced, Tulare, and Kings counties, and serves communities including but not limited to Clovis, Coalinga, Fresno, Madera, Porterville, Reedley, Selma and Visalia, as well as unincorporated areas.

Contact

Please direct questions concerning telephone numbering and area codes to staff at Numbering Staff.