Cal. Sts. & Hy. Code § 6510
If through error or otherwise the total amount for which the sale is made is less than that required by the provisions of this chapter, and the holder of the bond either is the purchaser at the sale and elects to accept the certificate of sale hereinafter mentioned, or accepts from the treasurer the sum derived from the sale made to some other purchaser, the fact that the sale was made for less than the amounts specified in this chapter shall not affect or invalidate the sale, and the acceptance of the certificate or of the sum derived from the sale shall be a waiver on the part of the holder of the bond, and in such case the amount received on the sale shall be the amount upon which redemption from the sale shall be calculated the same as if the sale had been made for the full amount authorized by this chapter.
Ca. Sts. and High. Code § 6510