U.S. President Donald Trump speaks about tariffs in the Rose Garden of the White House in Washington, DC, on April 2, 2025.
Carlos Barria | Reuters
The U.S. government could owe more than $175 billion in refunds to importers after the Supreme Court ruled in a 6-3 decision Friday that President Donald Trump’s unilaterally imposed tariffs were illegal, according to new estimates.
Because President Trump imposed the tariffs without Congressional authorization, a wide range of businesses could be reimbursed for tariffs already collected by the government.
The $175 billion return estimate from the Penn Wharton Budget Model was prepared at the request of Reuters. The model is a nonpartisan fiscal research group at the University of Pennsylvania.
Several importers already have lawsuits seeking refunds for the tariffs, citing lower court rulings that found President Trump’s tariffs illegal.
Friday’s Supreme Court ruling did not say the federal government could keep the funds it already collected from these duties, but it did not explicitly mention refunds.
The president invoked the International Emergency Economic Powers Act to impose the tariffs. He was the first president to use IEEPA for that purpose.
Chief Justice Brett Kavanaugh, one of three conservative high court members who opposed Friday’s ruling, warned of the potential logistical difficulties of having to refund duties already collected.
“In the meantime, however, the preliminary impact of the Court’s decision could be substantial,” Kavanaugh wrote in his dissent.
“The United States could be required to refund billions of dollars to importers who paid IEEPA tariffs, even though some importers may already be passing those costs on to consumers and others,” he said.
“As acknowledged at oral argument, the refund process is likely to be ‘chaotic,'” Kavanaugh wrote.
“Furthermore, according to the government, IEEPA tariffs have helped facilitate trillions of dollars worth of trade agreements, including with foreign countries such as China, the United Kingdom, and Japan,” he wrote.
“The court’s decision could create uncertainty regarding these trade agreements.”
“We estimate” IEEPA-related tariffs determined to be illegal account for “approximately 60% of the tariffs issued to date,” Brian LeBlanc, senior economist at PNC Financial Services Group, said in a LinkedIn post on Friday.
“This is a big deal. Until President Trump replaced these tariffs with alternative authorities, the tariffs only dropped from about 9.5% to about 5%,” LeBlanc wrote. “Refunds will be difficult, and we expect the Trump administration to replace most (if not all) of this lost tariff revenue.”
In December, U.S. Customs and Border Protection announced that $133.5 billion in collected duties are at risk of return.
That number would have increased further since then, as surcharges are still being levied.
