Cal. RTC § 3701

(a) Not less than 45 days nor more than 120 days before the proposed sale, the tax collector shall send notice of the proposed sale by certified mail with return receipt requested to the last known mailing address, if available, of parties of interest, as defined in Section 4675. The notice shall state the date, time, and place of the proposed sale, the amount required to redeem the property, and the fact that the property may be redeemed up to the close of business on the last business day prior to the date of the sale, and information regarding the rights of parties of interest to claim excess proceeds, as defined in Section 4674, if the property is sold and excess proceeds result from that sale.

(b) The tax collector shall make a reasonable effort to obtain the name and last known mailing address of parties of interest.

(c) The validity of any sale under this chapter shall not be affected if the tax collector’s reasonable effort fails to disclose the name and last known mailing address of parties of interest or if a party of interest does not receive the mailed notice.

(d) If the property subject to the notice required by this section is the subject of a bankruptcy proceeding, the notice shall constitute a “notice of tax deficiency” pursuant to Section 362(b)(9)(B) of Title 11 of the United States Code.