SEATTLE (AP) — The Washington Supreme Court has unanimously upheld a new tax on big banks aimed at providing essential services and helping improve the state’s regressive tax system.

The 1.2% business and occupation surtax — a tax added on top of other taxes — was passed by the Legislature in 2019. It applies to banks that make more than $1 billion in annual profits, but it is assessed only on their economic activity in Washington.

The banking industry sued, saying the tax discriminated against banks engaged in interstate commerce, in violation of the U.S. Constitution.

The justices ruled Thursday the tax doesn’t discriminate against out-of-state banks because it applies equally to those based in Washington or elsewhere.