Cal. Rev. & Tax. Code § 41030

The California Technology Agency shall determine annually, on or before October 1, a surcharge rate that it estimates will produce sufficient revenue to fund the current fiscal year’s 911 costs. The surcharge rate shall be determined by dividing the costs (including incremental costs) the California Technology Agency estimates for the current fiscal year of 911 plans approved pursuant to Section 53115 of the Government Code, less the available balance in the State Emergency Telephone Number Account in the General Fund, by its estimate of the charges for intrastate telephone communications services and VoIP service to which the surcharge will apply for the period of January 1 to December 31, inclusive, of the next succeeding calendar year, but in no event shall such surcharge rate in any year be greater than three-quarters of 1 percent nor less than one-half of 1 percent.