A premium finance agreement may provide for the payment by the insured of a delinquency charge of one dollar to a maximum of five percent of the delinquent installment that is in default for a period of five days or more except that if the loan is primarily for personal, family, or household purposes the delinquency charge shall not exceed five dollars.
If the default results in the cancellation of any insurance contract listed in the agreement, the agreement may provide for the payment by the insured of a cancellation charge equal to the difference between any delinquency charge imposed with respect to the installment in default and five dollars.
RCW 48.56.100