A recent U.S. Supreme Court ruling striking down tariffs imposed under the International Emergency Economic Powers Act (IEEPA) has triggered a wave of refund litigation and forced companies to rethink their tariff strategies, trade attorneys said during a webinar hosted by law firm Dykema.

The webinar, titled “2026 Tariff Turbulence: IEEPA Tariffs, Supreme Court Fallout & Refund Strategies,” was held Thursday and featured Dykema attorneys Joanne Zimolzak, John Rhoades and Tina Toma, who discussed the legal fallout from the court’s decision and what importers should do next.

Dykema is a Detroit-based national law firm founded in 1926 with more than 400 attorneys nationwide, providing legal services including litigation, corporate transactions, regulatory, tax, labor and employment, and intellectual property law.

The U.S. Supreme Court ruled earlier this year that tariffs imposed under IEEPA were unlawful because the statute does not grant the president authority to impose tariffs, attorneys said during the webinar.

“The court held that the word ‘regulate’ in IEEPA does not include the authority to impose tariffs,” Toma said. “Taxing imports is a distinct constitutional power that requires express delegation from Congress.”

The decision invalidated tariffs that had been imposed on imports from China, Canada, Mexico and dozens of other countries, affecting hundreds of billions of dollars in trade and setting off a complex process for companies seeking refunds on duties already paid.

The ruling was based in part on the court’s finding that IEEPA allows the president to regulate imports during a national emergency but does not explicitly authorize tariffs, which are considered a tax that requires clear congressional approval, according to the attorneys.

“The bottom line here is the executive orders imposing IEEPA tariffs are invalid and duties collected under those orders were assessed without legal authority,” Toma said.

A major focus of the webinar was the ongoing litigation in the U.S. Court of International Trade and the process for issuing refunds on previously collected tariffs.

“In terms of precedent for refunds of this scale… we’re looking at about $166 billion,” Rhoades said.

The refund claims tied to the invalidated tariffs could far exceed previous large-scale refund cases such as the harbor maintenance tax case, which involved about $2.8 billion in refunds and took years to resolve.

Customs and Border Protection is developing a new system to process refunds electronically, with a proposed process that would allow importers to submit claims through a portal, followed by automated validation and payment through the Treasury Department.

“Finalizing entries without tariffs is unprecedented in scale,” Rhoades said. “If it were to be done manually, it would require a review of over 70 million entries.”

The agency has indicated that implementing the system and reviewing tens of millions of entries will be a complex process, though early timelines suggested refunds could begin later this year.

One of the most important issues for importers is whether their entries have been liquidated, recently liquidated or finally liquidated, because that determines whether they are eligible for automatic refunds or must file protests or lawsuits to preserve their rights.

Importers generally have 180 days after liquidation to file a protest, attorneys said, making it critical for companies to track their entries and deadlines to avoid losing refund eligibility.

“The standard protest deadline is 180 days after liquidation… so just keep an eye on that so you don’t find yourself in a position where you have forfeited claims,” Zimolzak said.

Another key legal question still being debated is whether refunds will be limited to companies that filed lawsuits in the Court of International Trade or extended more broadly to importers with eligible entries.

“There’s kind of a divergence of views now in the position of the government and of the Court of International Trade, where the government has taken the position that refunds should be limited to companies that file claims in the Court of International Trade,” Zimolzak said.

Despite the Supreme Court decision, attorneys said companies should expect tariffs to remain a major part of U.S. trade policy, but imposed under more traditional legal authorities such as Section 232, Section 301 and Section 201, which require formal investigations and administrative processes.

The Trump administration has already imposed a temporary global import surcharge under Section 122 of the Trade Act, and additional tariff actions tied to national security, industrial policy and trade enforcement are likely.

The shift means companies may have more time to prepare for new tariffs but should still expect continued trade policy volatility.

Attorneys recommended companies take several immediate steps, including:

Tracking liquidation status of entries

Preserving refund rights through protests or litigation if necessary

Reviewing contracts for duty-sharing provisions

Evaluating supply chain exposure to future tariffs

Preparing internal response plans for new tariff actions

While the Supreme Court decision eliminated one category of tariffs, the broader trade environment remains uncertain, and companies should prepare for continued tariff policy changes in the years ahead.

The post Tariff turmoil: Refunds, lawsuits and new duties ahead appeared first on FreightWaves.