Missouri Revised Statutes Title XXVI. Trade and Commerce § 408.105. Precomputed loans, extensions, fee, limitations

(1) No extension may be taken on the first installment;

(2) No extension fee shall be collected more than one month prior to the due date of the earliest installment being deferred;

(3) No extension shall be collected for any partial payment; however, two dollars or less shall not be considered a partial payment;

(4) A minimum extension fee of one dollar will be allowed;

(5) In the event of  1 prepayment in full of the note or contract, the extensions shall be counted as months and computed as provided in section 408.170, based on this total, applied to all of the interest contracted for, plus the extension fees collected.