(a) An officer or employee of the Franchise Tax Board may not contact any person other than the taxpayer with respect to the determination or collection of the tax liability of the taxpayer without providing reasonable notice in advance to the taxpayer that contacts with persons other than the taxpayer may be made. The notice shall explain that a request may be made as provided in subdivision (b). A notice shall be valid for any third-party contacts made during the 12 months following the date of the notice. For any third-party contacts made after the expiration of the 12 months, an additional preliminary notice must be provided. This subdivision shall not apply if mail to the same address is returned undeliverable with no forwarding address. The notice shall not be required if the unpaid tax for which notice would otherwise be required under this paragraph is consolidated for collection purposes with a preexisting unpaid tax for which notice has been given under this paragraph with respect to that described preexisting unpaid tax of the person.