The US Supreme Court ruled 6–3 that President Trump’s global tariffs were illegal.

• The Court determined that the International Emergency Economic Powers Act (IEEPA) does not authorise the President to impose tariffs.

• Chief Justice John Roberts delivered the majority opinion.

• Justices Clarence Thomas, Samuel Alito, and Brett Kavanaugh dissented.

• The ruling may require the US government to refund approximately $150 billion in collected tariffs.

• The decision overturns:

  • “Reciprocal” country-by-country tariffs (e.g., 34% on China, 10% baseline globally).

  • 25% tariffs on certain goods from Canada, China, and Mexico.

• Tariffs imposed under separate laws (such as those on steel and aluminium) are not affected.

• President Trump could attempt to use alternative legal authorities to reimpose tariffs.

• Justice Kavanaugh stated the Court did not address how refunds should be administered.

• The UK Government is assessing the ruling’s impact but expects continued strong US trade relations.