California Code, Revenue and Taxation Code - RTC § 21026

(a) Except as otherwise provided in subdivision (b), for taxable years beginning on or after January 1, 1998, the board shall, not less than annually, mail a written notice to each taxpayer who has a tax delinquent account of the amount of the tax delinquency as of the date of the notice.

(b) Subdivision (a) shall not apply to accounts where a previously mailed notice to the address of record was returned to the board as undeliverable, or to accounts that are discharged from accountability pursuant to Article 2.5 (commencing with Section 12433) of Chapter 5 of Part 2 of Division 3 of Title 2 of the Government Code.