Any unauthorized insurer transacting insurance in this state shall be subject to a tax of 2% of premiums written in this state and to an additional regulatory fee of 0.5% on premiums written in this state. The tax required by this section shall be considered delinquent if not paid within 30 days after a copy of the computation of the tax by the commissioner is delivered to the insurer in the manner prescribed by law for the service of process.
MCL 500.451