Ala. Code § 8-8-13: Collection on Notes, Etc., Discounted at Higher Rate of Interest Than Eight Percent.

Except when otherwise permitted by law, any banker who discounts any note, bill of exchange, or draft at a higher rate of interest than eight percent per annum, not including the difference of exchange, cannot enforce the collection of the same, except as to principal; and if any interest has been paid, the same must be deducted from the principal and judgment entered for the balance only.