A U.S. Customs and Border Protection official testified in federal court Tuesday about the agency's system for refunding billions of dollars in tariffs that the Supreme Court ruled President Donald Trump imposed illegally on imports from other countries.

Court of International Trade Judge Richard Eaton held the hearing to examine CBP's plans for expanding its tariff refund process. The Justice Department has appealed Eaton's earlier order requiring the government to make all businesses that paid the invalidated tariffs eligible for refunds with interest, arguing only companies that were parties to the more than 2,500 lawsuits challenging the tariffs should receive refunds.

CBP launched an online refund system in April after Eaton ordered the agency in March to create a process for "all importers of record" to apply for their share of an estimated $166 billion collected before the Supreme Court struck down the tariffs. As of June 1, claims totaling $89.6 billion had been accepted for processing, with $20.6 billion in refunds already directed to the Treasury Department for payment.

The current system limits applications to businesses whose tariff bills were not finalized when the Supreme Court ruled in late February, or whose bills were settled within the preceding 80 days. Susan Thomas, CBP's executive assistant commissioner for trade, stated in a court declaration that the agency is developing methods to handle older refund cases but will not process claims beyond the 80-day window while the broader eligibility order remains on appeal.

The dispute centers on CBP's complex customs clearance process, where importers estimate tariffs owed and make deposits, which the agency then reviews and finalizes within 314 days to four years. Once goods are "liquidated," importers have 180 days to protest determinations before assessments typically become final.

Lawyers representing five companies in the original lawsuit argue it would be unconstitutional for their clients to receive different treatment than other importers who paid the same invalidated duties. They have requested the case be certified as a class action representing "potentially tens of thousands of identically situated importers." The Supreme Court previously ruled that Trump improperly used emergency powers to impose the tariffs, usurping Congress' authority over taxation.