Costco Tariff Lawsuit Seeks Refunds Before Dec. 15

Costco Wholesale Corporation (COST) filed a lawsuit in the U.S. Court of International Trade on or before December 2, 2025, seeking refunds and to block emergency tariffs imposed under the International Emergency Economic Powers Act (IEEPA) as the government prepares to finalize import entries.

Filing and Relief Sought

Costco’s complaint challenges the emergency tariffs imposed on goods from China, Mexico, Canada, and other countries, arguing that IEEPA does not authorize the president to create or raise tariffs. The statute does not mention the word “tariff,” and the company contends that interpreting IEEPA to permit duties raises constitutional nondelegation concerns because Congress must explicitly grant taxing authority.

The lawsuit seeks declaratory relief to invalidate the tariff orders, an injunction barring U.S. Customs and Border Protection (CBP) from applying the tariffs to Costco’s shipments going forward, and a refund of all duties paid under the emergency tariff program. Costco has paid these duties throughout 2025.

Both the U.S. Court of International Trade and the Federal Circuit previously ruled that the emergency-powers statute does not authorize the tariff orders. These decisions helped bring the issue to the Supreme Court, which heard oral arguments on November 5, 2025. A ruling is expected in early 2026.

At oral argument, several justices questioned the government’s position. Chief Justice John Roberts asked how a multibillion-dollar tariff regime could rest on statutory silence, while Justice Sonia Sotomayor questioned the revenue-raising nature of duties. Justice Amy Coney Barrett pressed parties on how reimbursement would operate. Plaintiffs pointed to administrative refund mechanisms such as 19 U.S.C. § 1514 protests and CBP refund pathways but acknowledged the court might limit relief to prospective remedies, which some scholars say could leave existing procedures inadequate to unwind collected charges.

Liquidation Deadline and Context

Costco faces a December 15, 2025, liquidation deadline, after which CBP will finalize import entries and lock in duty amounts. Once entries are liquidated, importers may lose the ability to challenge or recover those charges. One of Costco’s import entries has already been finalized, increasing the urgency of the refund claim.

The White House is preparing alternative tariff tools if courts reject the IEEPA approach. These include greater use of Sections 301 and 232 authorities, which address unfair trade practices and national security, respectively. Section 301 investigations can take up to nine months; a probe has been opened into Brazil. Section 122, which allows balance-of-payments tariffs, could be invoked quickly but carries a 15% cap and a 150-day limit and has not been used in modern practice. Section 338 could permit up to 50% country-level duties but is untested and lacks established procedural safeguards.

Other importers have pursued similar litigation. Learning Resources filed a challenge earlier in 2025, warning that emergency tariffs would sharply increase its annual duty bill. Apparel makers, automotive-parts suppliers, and consumer-goods distributors have also argued that the tariffs caused sudden cost increases and disrupted supply chains.

The compressed calendar and ongoing court review create immediate financial risk for importers who have paid under the emergency program. Whether retailers like Costco can recoup duties will depend on the Supreme Court’s ruling and how Customs and the administration unwind or replace the tariff framework.