Boeing Co. v. State of Washington, 747 F.2d 524 (9th Cir. 1975)
In Boeing Co. v.
Whether Washington State's method of calculating corporate tax burdens through its apportionment formula violated the Commerce Clause by unfairly taxing out-of-state income.
Under the Commerce Clause, a state's tax method must not subject taxpayers to unfair treatment or impose burdens on interstate commerce. Tax apportionment formulas must ensure that a company is taxed fairly and proportionately to the unambiguous connection of its income to the taxing state.
The Ninth Circuit held that Washington's apportionment formula was constitutionally permissible, affirming that it did not violate the Commerce Clause. The formula was determined to fairly apportion income reasonably related to the business conducted within Washington.
Boeing Co. v. State of Washington is an essential case for understanding the principles of state corporate taxation and the constitutional limits imposed by the Commerce Clause. It serves as a precedent for determining the balance between a state's right to tax and the protection against discrimination of interstate commerce. For law students, this case illustrates the practical applications of tax apportionment and the judicial interpretations that guide such state laws.