Cal. Government Code § 7473

(a) A customer may authorize disclosure under paragraph (1) of subdivision (a) of Section 7470 if those seeking disclosure furnish to the financial institution a signed and dated statement by which the customer: (1) Authorizes such disclosure for a period to be set forth in the authorization statement; (2) Specifies the name of the agency or department to which disclosure is authorized and, if applicable, the statutory purpose for which the information is to be obtained; and (3) Identifies the financial records which are authorized to be disclosed. (b) No such authorization shall be required by a financial institution as a condition of doing business with such financial institution. (c) Any officer, employee or agent of a state or local agency seeking customer authorization for disclosure of customer financial records shall include in the form which the customer signs granting authorization written notification that the customer has the right at any time to revoke such authorization, except where such authorization is required by statute. (d) (1) An agency or department examining the financial records of a customer pursuant to this section shall notify the customer in writing of such examination within 30 days of the agency or department’s receipt of any of the customer’s financial records, except that by application to a judge of a court of competent jurisdiction in the county in which the records are located upon a showing of good cause to believe that disclosure would impede the investigation, such notification requirements may be extended for two additional 30-day periods. Thereafter, by application to a court upon a showing of extreme necessity for nondisclosure, such notification requirements may be extended for three additional 30-day periods. At the end of that period or periods the agency or department shall inform the customer that he has the right to make a written request as to the reason for such examination. Such notice shall specify the financial records which were examined and, if requested, the reason for such examination. (2) Wherever practicable, an application for an additional extension of notification time shall be made to the judge who granted the first extension of notification time. In deciding whether to grant an extension of the notification time, the judge shall endeavor to provide the customer with prompt notification, consistent with the purpose of this chapter, and on the presumption that prompt notification is the rule and delayed notification the exception.