The lawsuit comes ahead of an upcoming Supreme Court ruling on the legality of Trump’s tariffs.

Costco has filed a lawsuit against U.S. President Donald Trump’s administration, seeking a full refund of the tariffs it paid this year before the U.S. Supreme Court weighs in on the legality of the tariffs.

the lawsuit, Submit on Fridayalso called for blocking the imposition of import tariffs.

Costco said the tariff issue needs to be addressed immediately because the deadline for refunds of taxes paid is Dec. 15. The lawsuit alleges that U.S. Customs and Border Protection denied the company’s request for an extension.

Costco did not specify how much it believes should be refunded.

“In the absence of their own judgment and judicial relief, importers, including the plaintiffs, who have paid IEEPA duties cannot guarantee the refund of illegally imposed duties,” the lawsuit states.

Costco also requested a moratorium on further receipts, according to the lawsuit filed in the U.S. Court of International Trade.

“Plaintiff seeks relief from the impending liquidation to ensure that his right to a full refund is not impaired,” the lawsuit states.

The wholesale warehouse giant joins other major companies including eyewear maker Ray-Ban and cosmetics company Revlon in suing the government. The law firm representing Costco is Crowell & Moring. The company declined Al Jazeera’s request for comment.

“They filed within the legal deadline to obtain (refunds) of tariffs that were (allegedly) illegally imposed,” Gregory Shafer, a professor of international law at Georgetown University Law School, told Al Jazeera.

Shaffer said the company has 180 days to protest the liquidation or the amount owed.

“Duty clearance is the final, official calculation and assessment of the duties, taxes and fees owed on imported goods.”

The White House has dismissed the lawsuit.

“The economic consequences of failing to uphold President Trump’s lawful tariffs are substantial, and this lawsuit highlights that fact. The White House expects the Supreme Court to resolve this matter quickly and appropriately,” White House spokesman Khush Desai said in a written statement provided to Al Jazeera.

Upcoming Supreme Court Decisions

The Supreme Court is weighing whether the White House has the authority to impose tariffs under the International Emergency Economic Powers Act (IEEPA).

The law gives the U.S. president the power to regulate imports during national emergencies. The main question is whether Trump’s tariffs meet these conditions. A decision is imminent, the date is not yet clear, as the justices hear arguments Nearly a month ago in early November.

Schaefer believes the court is likely to rule against the Trump administration.

“It looks like there will be at least four dissenting votes, and I have a feeling that Justice Gorsuch, given his concerns, will vote no,” Schaefer said, referring to Associate Justice Neil Gorsuch, whom Trump appointed to the Supreme Court during the president’s first term.

“Judging from the doubts, this decision is more likely to be detrimental to the Trump administration.”

During oral arguments at the November hearing, Gorsuch pushed back against the administration’s interpretation of IEEPA.

“The reality is, once Congress transfers power to the president, it cannot take it back,” Gorsuch said at the time.

“It’s a one-way ratchet that gradually but continuously increases the power of the executive branch and away from the people’s elected representatives.”

On Wall Street, Costco shares were up 0.2% in midday trading.