Cal. RTC § 11166

(a) On or before January 1 of the year that follows a year, or portion thereof, in which an assessment is imposed pursuant to this part, and annually thereafter, the Franchise Tax Board shall report to the department an estimate of the total amount of the revenue loss to the state that is expected to occur in the next calendar year, for a report given before January 1, or the current calendar year, for a report given on January 1, from deductions taken under the Personal Income Tax Law (Part 10 (commencing with Section 17001)) and the Corporation Tax Law (Part 11 (commencing with Section 23001)) for taxes paid or incurred as a result of an enacted tax being imposed pursuant to this part.

(b) On or before January 1 of the second year that follows a year, or portion thereof, in which an assessment is imposed pursuant to this part, and annually thereafter, the Franchise Tax Board shall report to the department a revision of the applicable previous estimate made pursuant to subdivision (a), based on actual filings and returns.