California Code, Revenue and Taxation Code - RTC § 19054

(a) If on any return or claim for refund of taxes imposed under Part 10 (commencing with Section 17001) or Part 11 (commencing with Section 23001), there is an overstatement of the credit for income tax withheld, or of the amount paid as estimated income tax, the amount so overstated which is allowed against the tax shown on the return or which is allowed as a credit or refund may be assessed by the Franchise Tax Board in the same manner as is provided by Section 19051 in the case of a mathematical error appearing on the return.

(b) No unpaid amount of estimated tax under Section 19025 or 19136 shall be assessed.