The U.S. Supreme Court’s recent ruling that that the International Emergency Economic Powers Act (IEEPA) does not authorize the President to impose tariffs has triggered what could become the largest tariff refund process in U.S. Customs history. Importers may have billions of dollars at stake in money owed to them.

The Court’s decision in Learning Resources, Inc. v. Trump invalidated tariffs imposed under IEEPA and immediately raised pressing operational questions for importers and supply-chain organizations.

Companies are now grappling with how previously collected duties will be refunded, how existing import entries will be treated, and what steps they must take to protect their ability to recover payments. For many importers, the ruling could translate into substantial refunds, but only if companies properly track their entries and navigate the evolving refund process.

Implementation of the ruling is now largely in the hands of the U.S. Court of International Trade (CIT) and U.S. Customs and Border Protection (CBP), which are working to determine how invalid tariffs will be removed from past entries and how refunds will be distributed.

The CIT Directs Implementation

With the constitutional question resolved, responsibility for overseeing implementation shifted to the CIT.

On March 4, the CIT issued a key order directing CBP to begin unwinding the invalid tariffs. It instructed CBP to:

• Liquidate unliquidated entries without applying IEEPA duties;
• Reliquidate entries that had been liquidated but were not yet legally final, and
• Begin issuing refunds with interest

The order also indicated that relief should extend broadly to importers whose entries were subject to the invalid tariffs, not just to companies that had filed suit with the CIT.

Shortly after issuing the directive, however, the Court temporarily paused immediate implementation, in response to CBP claiming that the scale of the refund effort could overwhelm existing systems.

CBP is now developing new functionality within its Automated Commercial Environment (ACE) to manage refunds more efficiently. Instead of adjusting individual entries one by one, it’s exploring systems that could calculate refunds at the importer level.

Under this emerging approach, CBP could aggregate total IEEPA duties paid by an importer; certify the refund amount, and coordinate with the U.S. Treasury to issue electronic payments to the importer of record, potentially with interest.

Officials have indicated that a refund portal and automated processing system could become operational in the coming months, although implementation timelines remain uncertain.

One practical implication is that many companies aren’t currently configured to receive electronic refunds from CBP. Importers may need to confirm that their ACE accounts and ACH payment information are properly set up before refunds can be issued.

Operational Questions Facing Importers

Even as the refund framework takes shape, several practical questions remain unresolved:

Which shipments qualify? Entries that remain unliquidated are the most straightforward cases. For these shipments, CBP can remove the invalid tariffs when the entries are finalized. Entries that have already been liquidated may require additional steps. Depending on the circumstances, importers may need to file protests or pursue claims to recover duties.

Will refunds be automatic? This remains unclear. Some interpretations of the Court’s orders suggest CBP may issue refunds automatically through mass reliquidation. Others indicate that importers might need to submit claims through a refund portal. Because of this uncertainty, some importers are preserving their rights through filings with the CIT, particularly when significant duties are involved.

How long will refunds take? Given the scale of the task, refunds are unlikely to occur quickly. Developing systems capable of calculating refunds across tens of millions of entries will several months. For supply-chain organizations, this creates financial planning and accounting challenges, particularly where tariffs were incorporated into product pricing.

A New Source of Supply-Chain Disputes

Another emerging question is who ultimately keeps the refund. Under Customs law, refunds will be issued to the importer of record. But many companies passed tariff costs downstream through higher prices, tariff surcharges or contractual adjustments.

If duties are refunded, distributors, retailers or customers may argue that those savings should be shared.

This dynamic could trigger disputes involving tariff-surcharge clauses, price-adjustment provisions and reimbursement obligations.

In some cases, existing contracts will determine how refunds are handled. In others, companies might need to renegotiate pricing arrangements across their supply chains.

The Supreme Court ruling also reshapes how future tariffs are likely to emerge in the U.S. By ruling that IEEPA can’t be used to impose tariffs, the Court removed an unconstrained way for a president to set tariffs quickly.

Tariffs remain a major policy tool. But future measures will likely rely more heavily on established statutes such as Section 301 (unfair-trade investigations), Section 232 (national security) and antidumping or countervailing duty proceedings.

For supply chains, the practical implication is that future tariffs may emerge more slowly and through formal investigations, rather than sudden emergency actions. That may give companies more time to monitor policy developments and adjust sourcing strategies before duties take effect.

What Can Be Done Now

While courts and agencies finalize the refund process, importers don’t need to wait to begin preparing. Immediate steps include the following:

Audit past import entries. Review import records to identify shipments that were subject to IEEPA tariffs, including entry numbers, duty amounts and tariff classifications.

Track liquidation status. Determine whether entries are unliquidated, liquidated or still within post-liquidation protest periods, to help identify potential refund pathways.

Ensure ACE access. Importers should confirm that their ACE accounts are active and that ACH payment information is registered so electronic refunds can be received.

Prepare refund calculations. Estimate potential refunds, including possible interest.

Consider protective court filings. Where large sums are involved, some importers are filing complaints with the CIT to preserve their rights if the refund process becomes more restrictive or delayed.

Review supply-chain contracts. Examine agreements with customers and suppliers to determine whether tariff refunds could affect pricing arrangements.

Companies that begin preparing now will be best positioned to navigate what’s likely to become the most complex tariff reimbursement process in U.S. Customs history. Key steps include:

• Analyzing historical import data and identifying entries affected by the invalid tariffs;
• Monitoring ongoing guidance from the courts and customs authorities, and
• Reviewing supply-chain contracts to understand how potential refunds may affect pricing or cost-sharing arrangements

As the refund process continues to take shape, companies that stay organized and engaged will be best positioned to recover duties owed and manage the ripple effects across their supply chains.

Jeffrey Sims is a partner at Seyfarth Shaw LLP.