When a nonexempt lender charges more interest than is allowed under Cal. Const. art. XV, sec. 1, the interest provisions of the loan agreement are unenforceable. The principal amount of the loan is deemed due on the maturity date of the loan, and all payments on the loan before then are credited against principal. However, if the loan is not fully repaid at maturity, the lender may collect 10% interest on unpaid amounts from the maturity date to date of judgment under Civ. Code 3289, so long as the loan is not secured by real property. If the loan has real property security, the lender may recover post-maturity interest at 7% under Cal. Const. art. XV, sec. 1.