WASHINGTON, D.C.: President Donald Trump has long touted the billions flowing into federal coffers from his sweeping tariffs. However, after two court rulings deemed his most significant levies unlawful, the cash could start flowing the other way, back to importers, not consumers.

If the Supreme Court upholds those rulings, the U.S. government may have to refund tens of billions of dollars to companies that paid the duties. Ordinary Americans who paid higher prices for goods because of the tariffs, however, would see no such relief.

"We're talking about hundreds of billions of dollars potentially in refunds affecting thousands and thousands of importers," said Luis Arandia, a trade lawyer at Barnes & Thornburg. "Unwinding all that will be the largest administrative effort in U.S. government history."

At issue are tariffs imposed under the 1977 International Emergency Economic Powers Act (IEEPA). Trump used the law to declare trade deficits and the cross-border flow of drugs and migrants a "national emergency" and slapped levies on nearly all trading partners, as well as specific duties on Canada, China, and Mexico.

A trade court in New York ruled in May that Trump had exceeded his authority, a decision largely upheld last week by the U.S. Court of Appeals for the Federal Circuit. The appellate court delayed its ruling until October to give the administration time to appeal to the Supreme Court, which it did on September 3.

Customs data shows that more than US$72 billion in IEEPA tariffs have been collected through August 24. If struck down, companies could seek refunds, though how the money would be repaid is unclear. "The options are everything from automatic refunds, to a formal application process, to new lawsuits," said Ted Murphy, a trade lawyer at Sidley Austin.

There is precedent. In the 1990s, courts struck down a harbor maintenance fee on exports and created a process for refunds, though without paying interest. Whether the government would owe interest on IEEPA refunds remains uncertain.

Trump has already warned against giving back the money, saying in August it would trigger "a GREAT DEPRESSION." Analysts expect fierce legal battles over who qualifies for refunds and whether repayment is feasible.

Consumers, however, won't be eligible. Tariffs are paid by importers, who often pass the costs along in higher prices. "It's the importer of record that is legally liable," Arandia said. "They would be the only ones with standing to get that money back."