U15. Does a unitary group of insurance companies have to file a combined MBT return?

No. Insurance companies are not specifically excluded from the definition of a unitary business group, found at MCL 208.1117(6), and thus may constitute a unitary business group. In practice, however, there is no practical effect of this possibility. The tax on authorized insurance companies is equal to 1.25% of gross direct premiums written on property or risk located or residing in Michigan. MCL 208.1235. Because the tax is only on property or risk located in Michigan there will be no traditional apportionment for insurance companies. Thus, even if an authorized insurance company is unitary with another authorized insurance company under MCL 208.1117(6), this will have no effect in calculating the tax. A combined return will not be necessary.