California Code, Civil Code - CIV § 3322

(a)(1) A broker of construction trucking services shall pay all transportation charges submitted by a motor carrier of property in dump truck equipment by the 25th day following the last day of the calendar month in which the transportation was performed, if the charges, including all necessary documentation, are submitted by the fifth day following the last day of the calendar month in which the transportation was performed. If there is a good faith dispute over a portion of the charges claimed, the broker may withhold payment of an amount not to exceed 150 percent of the estimated cost of the disputed amount.

(2) A broker who violates paragraph (1) shall pay to the motor carrier of property in dump truck equipment a penalty of 2 percent per month on the improperly withheld amount.

(3) In an action for the collection of moneys not paid in accordance with paragraph (1), the prevailing party shall be entitled to his or her attorney's fees and costs.

(1) A “broker of construction trucking services” means any person, excluding a licensed contractor, that, as a principal or agent, arranges for transportation services to be provided by an independent contractor motor carrier of property in dump truck equipment and who is responsible for paying the transportation charges of the motor carrier.

(2) A “motor carrier of property in dump truck equipment” means a motor carrier of property permitted by the Department of Motor Vehicles that hauls any type of construction commodity or material in dump truck equipment.