MeadWestvaco Corp. v. Illinois Department of Revenue

MeadWestvaco Corp. v. Illinois Dept. of Revenue, 553 U.S. 16 (2008), is a United States Supreme Court case concerning the extent a state may tax companies that are not based in their state.

Background
Mead, a corporation based out of Ohio, owned Lexis-Nexis, which was based out of Illinois. Mead sold Lexis, and Illinois maintained that Mead must pay them a proportionate capital-gains tax. Illinois asserted that Mead and Lexis were integrated to the extent required for the "unitary business rule". This rule allowed states to tax a proportionate share of the value generated by an interstate corporation.

Opinion of the Court
In a unanimous opinion written by Associate Justice Samuel Alito, the Supreme Court held that the two businesses were not integrated enough to be considered a "unitary business" and Illinois was not allowed to tax Mead on the Lexis sale.