Cal. Food & Agric. Code § 56302.5
Upon the following, a licensee operating as a dealer shall notify the seller on a form to be prescribed by the department, as to the requirements set forth in Sections 56302 and 56620:
(c) If payment is not made within 30 days when the contract is oral, irrespective of the agreed time of payment.
The dealer shall have the burden of proof as to the timely delivery of such a notice.
Such a notice shall only be required as to the first contract between any particular seller and dealer during any one calendar year.