California Code, Civil Code - CIV § 1670.12

(1) “Exclusive listing agreement” means any contract or agreement providing an exclusive right to list or sell residential real property, including:

(2) “Single-family residential property” means one of the following:

(b)(1) It is unlawful for an exclusive listing agreement regarding single-family residential property to last longer than 24 months from the date the agreement was made. This paragraph shall not apply to exclusive listing agreements entered into between a real estate broker and a corporation, limited liability company, or partnership.

(2) No exclusive listing agreement shall renew automatically, and any renewal of an exclusive listing agreement shall be in writing and be dated and signed by all parties to the agreement. It is unlawful for a renewal of an exclusive listing agreement subject to paragraph (1) to last longer than 12 months from the date the renewal was made.

(e)(1) An exclusive listing agreement that is made, or that is presented for recording or filing with a county recorder, in violation of this section is void and unenforceable. A homeowner who entered into any such agreement may retain any consideration received thereunder.

(2) A violation of this section constitutes a violation under Section 1770.

(3) Any person licensed pursuant to Division 4 (commencing with Section 10000) of the Business and Professions Code who violates any provision of this section shall be deemed to have violated that person's licensing law.