(a) Notwithstanding any other law, the service charge included in a retail installment contract, retail charge agreement, revolving charge agreement, or other retail charge agreement must be at the rate agreed upon by the retail seller and the buyer. (b) This section does not limit or restrict the method of computing the service charge, whether by way of add-on, simple interest, or otherwise, so long as that method is disclosed in the contract and agreed upon by the retail seller and the buyer.
Alaska Legal Code