Mich. Comp. Laws § 500.1912

Sec. 1912. If the surplus lines licensee acts in reliance on prior written authority from an eligible unauthorized insurer in accordance with section 1911(1)(a), or on a written or oral communication received in accordance with section 1911(1)(b), the licensee, within 30 days after the date on which the risk was bound or the insured or applicant was advised that coverage has been or will be obtained, shall deliver a policy, a written binder, a certificate, or other written evidence of the insurance, to the insured or the insured's representative.