31-1-107. Interest rate allowed by agreement. (1) Parties may agree in writing to the payment of any rate of interest that does not exceed the greater of 15% or an amount that is 6 percentage points per year above the prime rate published by the federal reserve system in its statistical release H.15 Selected Interest Rates for bank prime loans dated 3 business days prior to the execution of the agreement. Interest must be allowed according to the terms of the agreement.
(2) A loan that is not usurious when made is lawful for the duration of the loan, provided the loan agreement is not substantially changed. This subsection does not apply to loan renewals.
(3) The provisions of this section do not apply to regulated lenders as defined in 31-1-111.