Treasury has provided guidance on how to handle questions regarding when a member of a unitary business group has a different year end or is a member of the unitary business group for part of a tax year.  See Michigan Department of Treasury Frequently Asked Question U29 below.

1.         Taxpayer A makes 2008 MBT estimates as a non-unitary group member. Later it is determined A is a member of a Unitary Group.  How are A’s estimates handled? A's payments will be credited to the account number of the "designated member" of the "unitary business group" who will file the annual MBT return for and on behalf of the entire group.

2.         Taxpayer A makes 2008 MBT estimates on a non-unitary group basis. A is a member of Unitary Group ABCDEF.  A is a 12/31/08 FYE.  On 7/13/08, A is no longer a member of Unitary Group ABCDEF. How are A’s MBT estimate handled? 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 a combined return for that portion of the member's tax year during which the member was part of the unitary business group.  (Source: Treasury FAQ U29)  Therefore, taxpayer A would file as part of the ABCDEF unitary group for the period January 1, 2008 through July 13, 2008.  Taxpayer A would file a separate return for the period July 14, 2008 through December 31, 2008.  The estimated payments made by taxpayer A could be used on the separate return.

3.         Taxpayer A makes 2008 MBT estimates on a non-unitary group basis. A is a member of Unitary Group ABCDEF.  A is a 12/31/08 FYE.  On 7/13/08, A is no longer a member of Unitary Group ABCDEF. On 7/13/08 A becomes a member of AGHI.  How is A’s income included in ABDEF and AGHI? 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 a combined return for that portion of the member's tax year during which the member was part of the unitary business group.  (Source: Treasury FAQ U29)  Therefore, Therefore, taxpayer A would file as part of the ABCDEF unitary group for the period January 1, 2008 through July 13, 2008. Taxpayer A would also file as part of the AGHI unitary group for the period July 14, 2008 through December 31, 2008. 

Treasury FAQ U29.  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 208.1511 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, 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, its annual return is due April 30. 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.