J.R. Simplot Company v. Idaho State Tax

In this case we are called upon to determine whether the world-wide unitary income of a foreign subsidiary, which is not "taxable income" under Internal Revenue Code § 63, may be combined with the unitary business income of a domestic corporation and its subsidiaries in order to compute the apportionable amount of "Idaho taxable income." We hold that foreign source income may not be included in Idaho taxable income for purposes of I.C. § 63-3027 unless it also included in the definition of taxable income under the provisions of I.C. § 63-3022. Therefore we reverse.