Costco Wholesale Corporation has filed a major lawsuit against the Trump administration, launching a direct legal challenge to President Donald Trump’s sweeping tariff program and demanding full refunds for millions of dollars in duties the company says were unlawfully collected.
The complaint, filed in the U.S. Court of International Trade, accuses the administration of imposing tariffs that go beyond the authority granted to the President under federal law. Costco argues that Trump’s reliance on the International Emergency Economic Powers Act to levy new import duties was not only improper, but flatly illegal.
In the filing, Costco states that it has been required to pay large tariffs on goods imported from multiple foreign countries throughout 2025. The company contends that these tariffs stem from executive orders that Trump issued in February, March, and April, which placed additional duties on products from Canada, Mexico, China, and dozens of other U.S. trading partners.
According to the complaint, the courts have already signaled that the government’s use of IEEPA to impose tariffs does not hold up. “IEEPA does not authorize these tariffs,” Costco argues, pointing to a Federal Circuit decision in V.O.S. Selections v. Trump, which found that the statute cannot be used as a backdoor mechanism for setting nationwide tariff policy.
Costco’s lawsuit claims that while the Supreme Court has heard arguments in the V.O.S. Selections case and is expected to issue a ruling soon, importers are not automatically guaranteed refunds even if the tariffs are struck down. That uncertainty, Costco says, forced it to file its own case. Without immediate court intervention, Costco warns, its paid tariff entries will begin to “liquidate” on December 15, which would block the company from getting its money back.
In the filing, Costco also accuses U.S. Customs and Border Protection of refusing to extend the liquidation deadlines, leaving the retailer at risk of losing refund rights for duties it describes as unlawful. Costco says it plans to seek a preliminary injunction to halt liquidation while the case proceeds.
The lawsuit traces the entire timeline of Trump’s 2025 tariff program, beginning with the February orders that added new charges on Mexico, Canada, and China. Trump justified those tariffs on national emergency grounds, citing drug trafficking, synthetic opioid production, and illegal immigration. The President later expanded the program in April with a reciprocal tariff system that applied new fees to nearly all imports.
Costco argues that none of these actions are permitted under IEEPA, noting that tariffs have long been treated as a core congressional power. The complaint also lays out a backup argument that even if IEEPA were interpreted to allow tariffs, that interpretation would violate the Constitution because it would represent an “impermissible delegation” of congressional authority.
The company is asking the court to declare Trump’s tariff program unlawful, block CBP from enforcing the duties against Costco, and order the government to return all tariff payments already collected.
The lawsuit comes at a time when businesses across the country are watching the tariff fight closely. Costco says it has paid the tariffs continuously throughout the year and is seeking a full refund with interest.
