California Code, Insurance Code - INS § 2057

Under a contract of fire insurance, payment to the insured shall be made within 30 days after the amount of the loss and the liability of the company have been agreed upon or settled by the insured and the company in writing.

If the company fails to pay within the 30 days, the payment shall bear interest, beginning the 31st day, at the prevailing legal rate. The company also shall be liable for all costs of collection, including reasonable attorneys' fees, if legal action is necessary to obtain payment after the company has willfully failed to pay within the 30 days.