US customs to halt IEEPA tariffs after SC ruling, shifts duties

US Customs and Border Protection will stop collecting tariffs imposed under the International Emergency Economic Powers Act from early Tuesday, days after the US Supreme Court ruled the duties illegal.

The decision marks a legal shift in the Trump administration’s trade policy.

While one set of tariffs is being withdrawn, a new global import duty under a separate authority is taking effect at the same time.

The change affects customs systems, revenue flows, and potentially billions of dollars already paid by importers.

It comes as supply chains remain sensitive to policy changes and compliance risks.

It also forces companies to reassess compliance processes and adjust documentation for shipments arriving this week.

Importers must ensure that entries filed after the deadline reflect the updated tariff codes.

Tariff codes switched off

US Customs and Border Protection said it will halt collections of IEEPA-based tariffs at 12:01 a.m. EST, or 0501 GMT, on Tuesday.

In a message to shippers on its Cargo Systems Messaging Service platform, the agency said it would deactivate all tariff codes linked to President Donald Trump’s earlier IEEPA-related orders as of that time.

The move follows a US Supreme Court ruling on Friday declaring the IEEPA duties illegal.

However, collections continued at ports of entry for more than three days after the judgment.

The agency said it would provide additional guidance to the trade community through further Cargo Systems Messaging Service updates as appropriate.

New global levy

The halt to IEEPA tariff collections coincides with the introduction of a new 15% global tariff imposed by Trump under a different legal authority.

This new measure replaces the duties struck down by the Supreme Court. It takes effect at the same time the IEEPA tariff codes are deactivated.

CBP clarified that the collection halt applies only to tariffs imposed under the International Emergency Economic Powers Act.

Other trade measures remain in force, including tariffs under the Section 232 national security statute and the Section 301 unfair trade practices statute.

Those programmes are not affected by the Supreme Court ruling or the agency’s latest action.

Existing enforcement and collection procedures for those tariffs continue unchanged.

Revenue at stake

The Supreme Court decision has significant financial implications.

More than $175 billion in US Treasury revenue generated by the IEEPA tariffs could be subject to potential refunds.

That estimate was calculated by economists at the Penn-Wharton Budget Model using a ground-up forecasting model.

Their analysis showed that IEEPA-based tariffs were generating more than $500 million per day in gross revenue.

If courts determine that importers are entitled to reimbursement, a substantial portion of those funds may need to be returned.

The scale of potential repayments could affect federal revenue projections.

For now, CBP’s message focuses on stopping future collections under IEEPA while implementing the new global tariff.