The Supreme Court of the United States has declared sweeping import tariffs imposed by President Donald Trump illegal, ruling that they were enacted without proper congressional approval.

In a 6–3 judgment delivered on Friday, the Court held that the administration wrongly relied on emergency economic powers to impose broad trade duties. The justices said the Constitution grants Congress, not the president, the authority to levy tariffs.

Chief Justice John Roberts, writing for the majority, said major economic policies with wide national impact require clear legislative backing and cannot be introduced through executive action alone.

The ruling voids the tariffs and opens the door for affected businesses to seek refunds. Legal experts estimate potential claims could run into billions of dollars, though compensation will be determined by lower courts.

The decision is a major setback for Trump’s trade agenda and reinforces limits on presidential authority. It also signals that future administrations must secure congressional approval before introducing large-scale trade measures.

The White House has yet to issue an official response, while analysts say the ruling will reshape U.S. trade policy and executive power debates in the coming years.