Cal. RTC § 3728

Before holding any tax deed heretofore or hereafter given under this chapter or Chapter 8 (commencing with Section 3771), former Chapter 3 (commencing with Section 3475), former Chapter 4.3 (commencing with Section 3534), or former Sections 3897 and 3897d of the Political Code to be void, the court shall determine the correct amount of taxes, penalties and costs that should be paid upon redemption to discharge the tax and assessment liens of all taxing agencies and revenue districts had the purported tax sale not been held and the court shall order the former owner or other party in interest to pay that amount within six months as follows:

(a) To the purchaser, or his or her grantee or successor in interest, the amount of taxes, penalties and costs expended by him or her as determined by the court in pursuit of title to the property, and when the purchaser at that sale or the grantee in any deed for taxes or his or her grantee or successor in interest is in possession of that property in good faith and claiming the property under a tax deed, which is regular upon its face, and has made permanent improvements thereon, the court shall not make that decree until there has also been repaid to the purchaser or his or her grantee or successor in interest a sum, as determined by the court, equal to the amount by which the value of the property has been enhanced by those permanent improvements; and

(b) To the county tax collector, the balance, if any, of the correct amount as determined by the court that should be paid upon redemption, which shall be distributed by the county to the taxing agencies and revenue districts as redemption money.

If the amounts are not paid in accordance with the order the court shall not hold the tax deed void.