This map is a compilation of the final set of city and county boundary changes filed with the California State Board of Equalization in accordance with Government Code 54900 for each assessment roll year beginning with the 2021 roll year. Boundary corrections are included in the dataset according to information provided by the city, county, and/or LAFCO. These corrections may or may not have been corrected in the Board of Equalization's records. Each layer is considered FINAL as of June in the year noted by the layer name. The boundaries from 2021 through 2025 are based on the California State Board of Equalization's tax rate area maps and may not align with other sources. For the latest data, please view the "City and County Boundary Line Changes" map.

As of April 1, 2024, the maintenance of this map is provided by the California Department of Tax and Fee Administration (CDTFA) for sales and use tax purposes.