The purpose of this 830 CMR 63.32B.2 is to provide rules for the combined reporting of income as required by M.G.L. c. 63, § 32B. The M.G.L. c. 63, § 32B reporting requirement recognizes that a unitary business can be conducted not only through separate divisions of a single corporation but also through corporations related by common ownership such that in either instance, in the case of a multi-state business, it is appropriate and constitutionally permissible to apportion the resulting income of the unitary business even if that income arises from activities conducted outside the state. A combined report is a computational schedule that is generally required to be filed when a corporation that is subject to tax under M.G.L. c. 63 is engaged in a unitary business with one or more other corporations that are required to be included in a combined report under M.G.L. c. 63, § 32B. In such cases, in the case of a multi-state business, the combined report is required to calculate the corporation's taxable net income derived from the unitary business as its share, attributable to the commonwealth, of the apportionable income or loss of the combined group engaged in the unitary business.