No repairperson shall commence work for compensation without specific authorization from the customer or his or her agent, in accordance with all of the following requirements:
No work shall be done or parts supplied in excess of, or different from, the original written estimate without the separate oral or written consent of the customer. If the consent is oral, the repairperson shall make a notation on the work order and on the invoice of the date, time, name of person authorizing the additional work or change in work, and the telephone number called, if any, together with a specification of the additional parts and labor and the total additional cost.
The repairperson shall inform the customer orally, and conspicuously in writing on the work order, of the maximum time it will take the repairperson to reassemble the aircraft or its component if the customer elects not to proceed with the work. The repairperson shall not charge the customer for more time than the specified maximum time if the customer elects not to proceed with the work.
Ca. Bus. and Prof'l. Code § 9793