Exxon Corp. v. Department of Revenue of Wis.

Background

A large, vertically integrated oil company with headquarters in Houston did only marketing work inside Wisconsin while its exploration, production, and refining occurred elsewhere. The company used separate internal accounting that showed losses in the Wisconsin marketing district for 1965–1968. Wisconsin’s tax department audited the company, treated the business as a single integrated (unitary) enterprise, applied the State’s apportionment formula to the company’s total income, and assessed additional taxes. State tribunals and courts reached differing views before the Wisconsin Supreme Court found a unitary business and allowed apportionment.

Reasoning

The Court addressed whether the Constitution allows a State to tax part of a multistate company’s total income when only marketing occurs in that State. Relying on prior decisions, the Court held that a company’s internal accounting cannot by itself prevent a State from using an apportionment formula when the business functions are integrated. The Court found evidence of centralized services, exchange agreements, uniform branding and credit systems, and interdependence among departments, so the marketing activity was part of a unitary stream of income. Because there was a sufficient connection to Wisconsin and the formula produced a rational share of income, the State’s taxation did not violate constitutional limits. The Court also rejected the argument that the Commerce Clause required allocating production income only to the State where the oil or gas was produced.

Real world impact

The decision means States may apportion and tax a share of a multistate company’s total income when the company’s in-state activity is integrated with out-of-state production or refining. A company’s separate functional accounting will not automatically shield out-of-state income from apportionment. The Supreme Court affirmed the Wisconsin Supreme Court’s judgment.