Unitary Business Groups 7. How must a unitary business group file its combined return when members of the group have different tax years?

A taxpayer that is a unitary business group must file a combined return under MCL 206.691 using the tax year of the designated member. The combined return of the unitary business group must include each tax year of each member whose tax year ends with or within the tax year of the designated member. For example, Taxpayer ABC is a unitary business group comprised of three corporations: Corporation A, the designated member with a calendar tax year end, and Corporations B and C with fiscal years ending March 31, and September 30, respectively. Taxpayer ABC's tax year is that of its designated member. Thus, Taxpayer ABC's tax year ends December 31. That annual return must include the tax years of Corporations B and C ending March 31 and September 30.

A taxpayer that becomes a member of a unitary business group or ceases to be a member of a unitary business group during that member's tax year must file as part of the combined return for that portion of the member's tax year during which the member was part of the unitary business group. For example, if Corporation C from the above example ceased to be a member of Taxpayer ABC on July 31, Corporation C must include October 1- July 31 on Taxpayer ABC's annual return, but file as a separate taxpayer - or as part of a new unitary taxpayer - for the period August 1 - September 30.