California Code, Food and Agricultural Code (Formerly Agricultural Code) - FAC § 55880

It is a violation of this chapter if the licensee or applicant has failed or refused to file with the director a schedule of his charges for services in connection with any farm product which is handled on account of, or as agent for another. Any services rendered for which charges are made, if not filed with the director, shall be charged at cost, if not covered by a written contract. Cost-supporting data shall be available for verification.