Michigan Compiled Laws, Chapter 445. Trade and Commerce § 445.1209

Sec. 209. A home improvement installment contract may provide for the payment by the buyer of a delinquency and collection charge on each installment in default for a period of not less than 10 days in an amount not in excess of 5% of such installment or $5.00, whichever is less. Only 1 such delinquency and collection charge may be collected on any such installment regardless of the period during which it remains in default. A contract may also provide for the payment of court costs actually incurred and of attorney's fees not exceeding 20% of the amount due and payable under such contract if the attorney is not a salaried employee of the contractor or holder for collection.