California Code, Revenue and Taxation Code - RTC § 23501

(a) There shall be imposed upon every corporation, other than a bank, for each taxable year, a tax at the rate of 7.6 percent upon its net income derived from sources within this state on or after January 1, 1937, other than income for any period for which the corporation is subject to taxation under Chapter 2 (commencing with Section 23101), according to or measured by its net income.

(b) For calendar or fiscal years ending after June 30, 1973, the rate of tax shall be 9 percent instead of 7.6 percent as provided by subdivision (a).

(c) For calendar or fiscal years ending after December 31, 1979, the rate of tax shall be the rate specified for those years by Section 23151.