^{A shopper exits a Costco store in Centerville, Ohio, US, on Tuesday, Oct. 21, 2025.}

^{Kyle Grillot | Bloomberg | Getty Images}

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Costco has filed a federal lawsuit seeking to reclaim all tariffs it has paid this year under President Donald Trump’s “reciprocal” and “fentanyl” tariffs. With a major Supreme Court case underway that could determine whether those duties were legally imposed, the retailer is pushing for immediate protection to ensure it is not permanently locked out of recovering millions in overpaid import taxes.

Why Costco Sued

In its complaint to the U.S. Court of International Trade, Costco argues that it may lose the chance to recover the tariffs it has already paid because of a looming procedural deadline. The company pointed to the December 15 liquidation date, which finalizes the government’s calculation of duties owed. Once liquidation occurs, importers often cannot reverse or protest the finalized amounts.

Costco said U.S. Customs and Border Protection rejected its request to postpone that date. Because liquidation can eliminate the right to a refund even when a tariff is later deemed unlawful, Costco is taking legal action to preserve its ability to reclaim the money.

The company did not specify in its filing how much it believes it is owed, but industry analysts estimate that large importers like Costco could be exposed to tens of millions of dollars in tariff liabilities under the contested orders.

The Tariffs at the Center of the Dispute

Trump imposed the tariffs under the International Emergency Economic Powers Act, a law intended to address national security threats. The administration used it to justify broad duties on imports from many U.S. trading partners, including Canada, China and Mexico. These tariffs were promoted as tools to counter unfair trade practices and combat the flow of fentanyl-related products.

More than a dozen companies have filed nearly identical lawsuits, all attempting to safeguard their potential rights to refunds if the Supreme Court determines that the tariffs were illegally imposed. Many of these businesses import large volumes of consumer goods and industrial materials affected by the emergency orders.

Lower Courts Have Already Ruled the Tariffs Unlawful

Earlier this year, the U.S. Court of Appeals for the Federal Circuit upheld a decision from the Court of International Trade, ruling that the president does not have authority under IEEPA to impose tariff systems of this scale. In a 7–4 decision, the court said the Constitution grants taxing and tariff powers exclusively to Congress.

The ruling directly challenged the Trump administration’s use of emergency powers, describing tariffs as “core Congressional authority.” The administration appealed, sending the case to the Supreme Court on an expedited basis.

Supreme Court Signals Skepticism

During oral arguments on November 5, several justices questioned the administration’s interpretation of IEEPA. While the court has not set a clear timeline for its decision, legal experts expect a ruling that could reshape presidential authority in trade policy.

The outcome could carry significant financial consequences. The administration has warned that if the tariffs are overturned, the government may owe hundreds of millions of dollars in refunds to importers.

Costco’s Position

Costco emphasized in its filing that importers cannot assume they will automatically receive refunds for unlawful tariffs. Instead, they must secure their own legal judgments. The company argued that acting now is essential to protect its rights.

The lawsuit states that without immediate judicial relief, Costco and other importers could permanently lose access to refunds even if the Supreme Court rules the tariffs unconstitutional.

White House Response

White House spokesman Kush Desai defended the tariff program, saying that striking down the duties could carry significant economic consequences. He argued that the lawsuit illustrates the stakes of whether the emergency tariffs remain in place and said the administration looks forward to the Supreme Court’s final decision.

Costco has not yet responded publicly to requests for comment, but trade experts say the company’s actions reflect growing concern among major importers as the legal battle reaches its final stage.

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Costco’s lawsuit highlights the escalating tension between importers, the White House and the courts over the scope of presidential trade authority. While the Supreme Court reviews one of the most consequential tariff cases in decades, companies are scrambling to protect their financial interests before key deadlines close the door on potential refunds.