Cal. Revenue and Taxation Code § 41132

(a) Except as otherwise provided by law, any person who is engaged in the business of preparing, or providing services in connection with the preparation of, returns under Chapter 4 (commencing with Section 41050), or any person who for compensation prepares any such return for any other person, and who knowingly or recklessly does either of the following, shall be guilty of a misdemeanor, and, upon conviction thereof, shall be fined not more than one thousand dollars ($1,000) or imprisoned no more than one year, or both, together with the costs of prosecution: (1) Discloses any information furnished to him or her for, or in connection with, the preparation of the return. (2) Uses that information for any purpose other than to prepare, or assist in preparing, the return. (b) Subdivision (a) shall not apply to disclosure of information if that disclosure is made pursuant to the person’s consent or pursuant to a subpoena, court order, or other compulsory legal process.