Cal. Rev. & Tax. Code § 2910.1

(a) The tax collector may, no later than 30 days prior to the date on which taxes are delinquent and as soon as reasonably possible after receipt of the extended assessment roll, mail or electronically transmit a tax bill for every assessment on the unsecured roll on which taxes are due, unless the total tax bill amount due is too small to justify the cost of collection.
(b) Failure to receive a tax bill shall not relieve the lien of taxes, nor shall it prevent the imposition of penalties imposed by this code. However, the penalty imposed for delinquent taxes as provided by any section in this code shall be canceled if the assessee does either of the following:
1. (1) Convinces the tax collector that the assessee did not receive the tax bill mailed to the address provided on the tax roll or electronic address provided and authorized by the taxpayer to the tax collector.
2. (2) Demonstrates to the tax collector that the delinquency is due to the tax collector’s failure to mail or electronically transmit the tax bill to the address provided on the tax roll or electronic address provided and authorized by the taxpayer to the tax collector.