Mich. Comp. Laws § 445.1854: Charge, collection, and receipt of interest rate or finance charge; maximum rate; computation.

Sec. 4.

Except as provided in subsection (2), a regulated lender may charge, collect, and receive any rate of interest or finance charge for an extension of credit not to exceed 25% per annum.

A depository institution may charge, collect, and receive any rate of interest or finance charge for a credit card arrangement.

Except for a fee or charge provided for in section 6 or 7, in connection with an extension of credit made to an individual for personal, family, or household purposes, the interest or finance charge that is calculated on the principal balance shall be computed only on the basis of the unpaid balance.