California Code, Revenue and Taxation Code - RTC § 3693

(a) With the exception of the sealed bid sale procedures authorized under Section 3692and of the procedures authorized in subdivisions (b) and (c), all sales pursuant to this chapter shall be at public auction to the highest bidder. The amount of the high bid shall be paid by any method of payment authorized by Section 2502, 2503.2, or 2504, which method is at the discretion of the tax collector. Unless otherwise specified by the tax collector, payment is due on or before the close of auction.

(b) For nonresidential commercial property, if the highest bidder does not consummate the sale within the time period determined by the tax collector, the tax collector may offer the property to the next highest bidder at their bid price.

(c) If a sale occurs at a public auction for a parcel of property subject to this chapter and the sale is unconsummated, if the next public auction for that parcel of property occurs more than one year after the date of that first auction and the highest bidder does not consummate that subsequent sale within the time period determined by the tax collector, the tax collector may offer that property, regardless of type, for sale to the next highest bidder at their price.

(d) The tax collector may require a person to submit a deposit, by any method of payment authorized by Section 2502, 2503.2, or 2504, for the purposes specified in this subdivision. A tax collector requiring a deposit pursuant to Section 3693.1 may determine, and shall provide public notice before the date of the sale upon determining, all of the following:

(e) This section shall remain in effect only until January 1, 2029, and as of that date is repealed.