California Code, Government Code - GOV § 22797

(a) The board or an authorized representative may perform audits of each employer and may, at a specified time and place, require the employer to provide information or make available for examination and copying books, papers, data, and records, including, but not limited to, personnel and payroll records, as deemed necessary by the board to determine compliance with the provisions of this part.

(b) Before initiating an audit, the board shall notify the subject of the audit of the estimated time required to complete the audit. The estimate shall be based upon various factors, including, but not limited to, the following:

(c) If an audit requires an excess of the time estimated, the board may assess a reasonable charge upon the employer to recover additional costs incurred for the excess time to complete the audit. A contracting agency shall not be assessed for delays during the course of an audit that are reasonably outside of the agency's control.

(d) The information obtained from an employer shall remain confidential.