US Supreme Court’s tariff ruling: what next for Ireland?

Following the US Supreme Court’s decision to invalidate Trump’s tariffs, John O’Loughlin examines Europe’s response and the implications for Ireland

On Friday 20 February 2026, the US Supreme Court issued its decision on tariffs imposed by US President Donald Trump under the International Emergency Economic Powers Act (IEEPA), which have so far generated more than $130 billion in tariff revenues.

The IEEPA provisions, announced in April 2025, gave Trump broad economic authority to address national emergencies declared under the National Emergencies Act, such as the Fentanyl crisis.

Trump also used the IEEPA to implement a broad range of tariffs on countries around the world.

In its 170-page decision, the US Supreme Court has held that the IEEPA does not authorise Trump to impose tariffs, and that the US President does not have the legal authority to impose tariffs.

It also states that the IEEPA’s grant of authority to “regulate … importation” does not include the power to impose tariffs, emphasising that the power to do so is “very clear[ly] … a branch of the taxing power” reserved for Congress under Article I of the US Constitution.

As a result, Trump’s IEEPA-based tariff actions have been deemed invalid.

From an implementation perspective, the White House has issued an Executive Order: “Ending Certain Tariff Actions” on 20 February, instructing the applicable agencies to “take all appropriate steps to end the additional ad valorem duties”.

Stemming from this, the US Customs and Border Protection (CBP) agency has issued guidance confirming that IEEPA tariffs will be removed from 24 February.

IEEPA refunds

Stemming from the Supreme Court decision, importers that have paid tariffs imposed under the IEEPA, should be subject to a refund of duties paid.

However, the opinion of the Court did not go into any detail on how such refunds are to be processed, and the mechanism of this refund process is still to be fully clarified with further guidance from CBP expected.

New global 15 percent tariff

Following the release of the Supreme Court decision striking down the IEEPA tariffs, Trump held an impromptu press conference, announcing that he would impose an additional 10 percent tariff on all imports within a matter of days, stating that “other alternatives will now be used to replace the ones that the court incorrectly rejected”.

Following this press conference, the White House issued a proclamation and fact sheet, Imposing a Temporary Import Surcharge to Address Fundamental International Payments Problems, outlining the imposition of a global 10 percent tariff, under Section 122 of the Trade Act of 1974, to take effect from 24 February.

However, such tariffs can remain in effect for just 150 days before requiring approval from Congress for any extension.

Further to this, on 21 February, President Trump wrote in a Truth Social post: “I, as President of the United States of America, will be, effective immediately, raising the 10 percent Worldwide Tariff on Countries, many of which have been ‘ripping’ ‌the US off for decades, without retribution (until I came along!), to the fully allowed, and legally tested, 15 percent level.”

While no further Executive Order, Proclamation or Fact Sheet has been released in respect of this increase to 15 percent, it is expected that such an order will be released with the 15 percent rate applying from this point onward, in addition to most-favoured-nation rates, for 150 days, until late August.

Government reaction

Unsurprisingly, the Supreme Court decision has generated considerable interest and discussion among governments around the world and the wider business community.

Following the announcement of the decision, EU Commission Deputy Chief Spokesperson Olof Gill said the EU remains in close contact with the US administration and outlined the need for stability.

“Businesses on both sides of the Atlantic depend on stability and predictability in the trading relationship,” Gill said. “We therefore continue to advocate for low tariffs and to work towards reducing them.”

In a statement released on 20 February, Ireland’s Minister for Foreign Affairs and Trade, Helen McAtee, stressed that “open, stable and predictable trade remains essential for economic growth, investment and jobs in Ireland.”

Additionally, as reported by RTÉ, Tánaiste and Minister for Finance Simon Harris said “low tariffs are in everyone’s interests and, at a European level, we will continue to engage with our US counterparts in order to promote measures that work for all”.

McEntee further stated; “bilateral trade, investment and economic cooperation deliver enormous economic benefits and we will always work towards that goal.”

On 22 February, in a statement released by the European Commission on the judgment of the Supreme Court, the Commission stated:

“A deal is a deal. As the United States’ largest trading partner, the EU expects the US to honour its commitments set out in the Joint Statement—just as the EU stands by its commitments.

“In particular, EU products must continue to benefit from the most competitive treatment, with no increases in tariffs beyond the clear and all-inclusive ceiling previously agreed.”

Speaking to Politico, Bernd Lange, chair of the European Parliament’s trade committee stated that President Trump’s imposition of a 15 percent global tariff following Friday’s high court defeat was “a clear breach of the deal we had agreed”.

Lange further advised, in respect of the ongoing EU legislative proposal to reduce tariffs on a large range of US goods imported to the EU, that he will “propose that we suspend ratification of the agreement for the time being”.

John O’Loughlin is Tax Partner at PwC Ireland