The department may require that a combined report include the income and associated apportionment factor or factors of any person who is not otherwise included in a combined group under this subsection, but who is a member of a unitary business, in order to reflect proper apportionment of income of the entire unitary business. The department may require that a combined report include the income and associated apportionment factor or factors of persons that are not corporations.

If the department determines that the reported income or loss of a member of a combined group engaged in a unitary business with any person not otherwise included in the combined group under this subsection represents an avoidance or evasion of tax by the person or the combined group member, the department may require all or any part of the income or loss and associated apportionment factor or factors of the person be included in or excluded from the combined report for the unitary business or may require the use of a different apportionment factor or factors. The department may require that a combined report include or exclude the income or loss and associated apportionment factor or factors of persons that are not corporations.

The authority granted under this paragraph is in addition to, and not a limitation of or dependent on, the provisions in this chapter enacted to prevent tax avoidance or evasion or to clearly reflect the income of any person. Any determination by the department under this paragraph is presumed correct and the person challenging the determination has the burden of proving by clear and convincing evidence that the determination is incorrect.