Generally, a unitary business group is a group of related persons whose business activities or operations are interdependent. More specifically, a unitary business group is two or more persons that satisfy both a control test and one of two relationship tests. MCL 208.1117(6). A unitary business group is a single taxpayer under the MBT and must file a combined return. MCL 208.1117(5), 208.1511. Foreign persons and foreign operating entities cannot be part of a unitary business group.

Control Test. The control test is satisfied when one person owns or controls, directly or indirectly, more than 50% of the ownership interest with voting or comparable rights of the other person or persons. Indirect ownership is generally determined using IRC 318 or analogous authority, except that the Department will apply IRC 318 to all forms of ownership interests, such as partnership and membership interests, and not just corporate stock.

A parent-subsidiary controlled group of entities satisfies the control test. A parent-subsidiary controlled group of entities means any group of one or more chains of entities connected through ownership with a common parent if (1) the common parent directly owns more than 50% of the ownership interest with voting or comparable rights of at least one other entity, and (2) an ownership interest meeting the more than 50% test in each entity other than the common parent must be owned directly by one or more of the other entities. For example, Corporation A owns 51% of Corporation B, which owns 51% of Corporation C, which owns 51% of Corporation D. The common parent owns more than 50% of the stock in at least one other entity (Corporation B), and more than 50% of the stock of each entity other than the common parent is owned by at least one other entity in the chain. Thus, Corporations A, B, C, and D are part of a parent-subsidiary controlled group of entities and satisfy the control test for unitary business groups.

Similarly, a brother-sister group of entities may satisfy the control test through the indirect ownership rules of IRC 318. For example, one corporation of a pair of corporations wholly owned by an individual will indirectly own and control 100% of the other through IRC 318.

Relationship Tests. In addition to satisfying the control test, the group of persons must have business activities or operations that (1) result in a flow of value between or among persons in the group, or (2) are integrated with, are dependent upon, or contribute to each other.

Flow of value is established when members of the group demonstrate one or more of functional integration, centralized management, and economies of scale. Examples of functional integration include common programs or systems and shared information or property. Examples of centralized management include common management or directors, shared staff functions, and business decisions made for the group rather than separately by each member. Examples of economies of scale include centralized business functions and pooled benefits or insurance. Groups that commonly exhibit a flow of value include vertically or horizontally integrated businesses, conglomerates, parent companies with their wholly owned subsidiaries, and entities in the same general line of business. Flow of value must be more than the mere flow of funds arising out of passive investment.

Businesses are integrated with, are dependent upon, or contribute to each other under many of the same circumstances that establish flow of value. However, this alternate relationship test is also commonly satisfied when one entity finances the operations of another or when there exist intercompany transactions, including financing.