In Arizona, a "unitary business that files a combined return shall use an apportionment formula that combines the property, payroll, and sales figures of all of the unitary group members before calculating the factors." A.C.C. R15-2D-404(B). Arizona also recognizes another method by which multiple corporations could file a single state return -- the consolidated return. Federal tax law has allowed a consolidated return for some time, see 26 U.S.C. 1501 et seq., but Arizona law did not allow the practice before 1994. 1994 Ariz. Sess. Laws, ch. 41, 26 (codified as A.R.S. 43-947). the Arizona statute allows an affiliated group of corporations that files a federal consolidated return to do the same for Arizona. The common parent of the corporate group elects to "consolidate the taxable income of all members of the affiliated group, regardless of whether each member is subject to tax under" the Arizona income tax code. A.R.S. 43-947(A). Under federal law, an affiliated group generally means a chain of corporations with a common parent owning and controlling at least 80% of each subsidiary. 26 U.S.C. 1504 (2006). All members of the affiliated group, as that term is defined in federal law, must be included in the consolidated return. 26 U.S.C. 1501 (2006). The Arizona statute also provides that an affiliated group shall allocate and apportion its income to Arizona under UDITPA, and for such purposes "the Arizona affiliated group is considered to be and shall be treated as a single taxpayer." A.R.S. 43-947(F); see also A.A.C. R15-2D-404(C) ("An Arizona affiliated group that files a consolidated return shall use an apportionment formula that combines the property, payroll, and sales figures of all of the members of the Arizona affiliated group before calculating the factors."). A significant difference between a combined report and a consolidated return is that the corporations included in the consolidated return need not constitute a unitary business. A consolidated return may include corporations having no connection to Arizona and engaged in businesses completely separate from other members of the group.