US President Donald Trump has appealed to the US Supreme Court to overturn a lower court ruling that declared many of his sweeping tariffs illegal.

The petition follows a 7-4 decision by the US Court of Appeals for the Federal Circuit, which ruled that Trump exceeded his authority by imposing tariffs on nearly all trading partners under the International Emergency Economic Powers Act (IEEPA). The judges said tariff-setting is a core power of Congress, not the executive branch.

In May, the Court of International Trade had also found the tariffs unlawful, prompting the Trump administration to seek higher judicial review.

According to filings submitted by Solicitor General John Sauer, delaying a Supreme Court ruling until 2026 could mean that between $750 billion and $1 trillion in tariffs will have already been collected. Sauer argued that reversing them later would cause “significant disruption” to the US economy.

As of August 24, American businesses had paid over $210 billion in tariffs now considered unlawful by lower courts. If the Supreme Court upholds those rulings, the US Treasury may be forced to refund massive sums in tariff revenue.

Trump imposed the tariffs after declaring a national emergency in April, claiming that trade imbalances had weakened domestic manufacturing and posed a national security threat. His administration argued that the IEEPA gave the president broad discretion to act in emergencies.

The appeals court, however, temporarily paused enforcement of its decision until October 14, giving Trump time to appeal. The Supreme Court is now being asked to decide whether presidents have unilateral authority to levy sweeping tariffs without congressional approval.

The outcome could reshape the balance of power on trade policy between Congress and the White House.