Cal. Rev. & Tax. Code § 3693.1
Notwithstanding Section 3693, the tax collector may make the sale of any property sold under this chapter a cash or deferred-payment transaction. If the tax collector approves the sale as a deferred-payment transaction, the tax collector may require a deposit in the amount of five thousand dollars ($5,000) or 10 percent of the minimum bid price, whichever is greater. The balance of the purchase price shall be paid by any method of payment authorized by Section 2502, 2503.2, or 2504, as specified by the tax collector and within a period specified by the tax collector not to exceed 90 days from the date of the close of auction as a condition precedent to the transfer of title to the purchaser. If the purchaser was required to pay a deposit prior to the date of the sale, the deposit shall be applied toward the purchase price of the property. Failure on the part of the successful bidder to consummate the sale within the period specified by the tax collector shall result in the forfeiture of the deposit and all rights he or she may have with respect to that property. Any forfeiture of deposit shall be distributed to the county general fund and shall not apply to outstanding delinquent taxes. Upon forfeiture the right of redemption shall revive.
Ca. Rev. and Tax. Code § 3693.1