Dec. 1, 2025, 5:15 PM ESTBy Steve Kopack and Gary GrumbachCostco Wholesale has filed a lawsuit against the Trump administration, asking the Court of International Trade to consider all tariffs collected under the International Emergency Economic Powers Act unlawful.The company said in a Nov. 28 filing that it is seeking a “full refund” of all IEEPA duties paid as a result of President Donald Trump’s executive order which imposed what he called “reciprocal” tariffs.“Because IEEPA does not clearly authorize the President to set tariffs…the Challenged Tariff Orders cannot stand and the defendants are not authorized to implement and collect them,” Costco’s lawyer writes in the lawsuit.The legality of Trump’s sweeping tariff agenda is currently under review by the Supreme Court. In early November oral arguments, justices appeared skeptical about the government’s case to let them continue.Both conservative and liberal justices asked tough questions of U.S. Solicitor General D. John Sauer, though some of the conservatives seemed more sympathetic to his arguments.Trump became the first president ever to use the IEEPA law to impose import duties. Lower courts earlier ruled against the administration’s use of the law but kept the tariffs in place while the case was argued.Costco does not say in the filing how much the duties imposed by Trump have cost the company, but a total of nearly $90 billion has been paid by importers under the IEEPA law according to U.S. Customs and Border Protection data through late September. In May, on the company’s earnings call, Costco chief financial officer Gary Millerchip told investors that about a third of Costco’s sales in the U.S. are imported. Millerchip said items imported from China represented about 8% of total U.S. sales.Millerchip said that while the wholesaler was seeing a direct impact from tariffs on imports of some fresh food items from Central and South America, the retailer decided not to increase prices “because they are key staple items” for its customers.Some of those fresh food items included pineapples and bananas. “We essentially held the price on those to make sure that we’re protecting the member,” he said.In September, Millerchip told analysts: “We continue to work closely with our suppliers to find ways to mitigate the impact of tariffs, including moving the country of production where it makes sense and consolidating our buying efforts globally to lower the cost of goods across all our markets.”Through the end of October, a total of $205 billion in tariffs has been collected by the government.With Friday’s lawsuit, Costco becomes the latest major company to seek tariff refunds through the courts.Global cosmetics giant Revlon, eyeglass maker EssilorLuxottica, motorcycle manufacturer Kawasaki, canned foods seller Bumble Bee, Japanese auto supplier Yokohama Tire and many smaller firms have also filed similar suits. Steve KopackSteve Kopack is a senior reporter at NBC News covering business and the economy.Gary GrumbachGary Grumbach is an NBC News legal affairs reporter, based in Washington, D.C.