Louisiana Revised Statutes Tit. 6, § 969.15. Maximum delinquency charges

(1) Five percent of the amount of the installment in default, or ten dollars, whichever is greater.

(2) The deferral charge that would be permitted to defer the unpaid amount of the delinquent installment for the period that it is delinquent.

B. (1) A delinquency charge may be collected only once on an installment or other payment however long it remains delinquent. No such delinquency charge may be collected if the installment or other payment has been deferred and a deferral charge has been paid or incurred, provided that the deferred payment is paid within ten days of its deferred date. Such a delinquency charge may be collected at the time it accrues or at any time thereafter.

(2) No such delinquency charge may be collected on an installment or other regular payment that is paid in full within ten days after its scheduled due date even though an earlier maturing installment or other payment or a delinquency charge on an earlier installment or other payment may not have been paid in full. For purposes of determining delinquency, payments are deemed to be applied first to current installments or other payments due and then to delinquent installments or other payments and then to delinquency and other charges.

(3) An extender of credit is prohibited from levying or collecting any delinquency charge on a payment when the only delinquency is attributable to delinquency charges assessed on earlier installments, and the payment is otherwise a full payment for the applicable period and is paid on its due date or within an applicable grace period.

(4) Nothing in this Section shall be construed to prohibit the extender of credit from assessing and collecting a loan finance charge or credit service charge on any delinquency or deferral charges not paid when due. Such loan finance charges or credit service charges shall not exceed the contract rate of interest charged on the motor vehicle credit transaction.