Charges in excess of those set forth in a rate filing which has become effective may be made when such filing includes a statement that such charges may be made in the event unusual insurance risks are assumed or unusual services performed in the transaction of the business of title insurance; provided, that such charges are reasonably commensurate with the risks assumed or the costs of the services performed and provided further that each person or entity obligated to pay all or any part of such charges consents thereto in writing in advance.
Ca. Ins. Code § 12401.8