In a significant legal development, the U.S. Supreme Court has declared that the tariffs imposed by former President Donald Trump on Canada and various other nations are unlawful. However, this ruling does not signify a cessation of Trump’s contentious global trade policies. The decision specifically targets tariffs enacted under emergency powers, including Trump’s controversial “reciprocal” tariffs and additional duties related to fentanyl imports from Canada. These tariffs now stand invalidated, restricting Trump’s ability to impose further tariffs under the same authority.
Tariff Landscape Post-Ruling
The Supreme Court’s decision primarily impacts two lawsuits challenging the application of the International Emergency Economic Powers Act (IEPPA), a law dating back to 1977 that permits the President to regulate economic transactions during declared emergencies. Trump had previously invoked this law to justify tariffs in response to an emergency regarding fentanyl trafficking and to address trade deficits with numerous nations.
At the time of the ruling, Canada was subjected to a hefty 35% tariff on fentanyl imports, alongside a 10% tariff on energy and fertilizer products. Notably, goods traded under the Canada-U.S.-Mexico Agreement (CUSMA) were exempt from these tariffs, a point emphasised by Canadian Prime Minister Mark Carney, who noted that approximately 85% of Canadian exports to the U.S. fall under this exemption.
Remaining Tariffs and Future Actions
Despite the Supreme Court’s ruling, other tariffs imposed by Trump remain intact. These include sector-specific tariffs enacted under Section 232 of the U.S. Trade Expansion Act, which allows for tariffs on foreign imports deemed a risk to national security. Existing tariffs under this section include a 50% duty on steel, aluminium, and copper, as well as a 25% tariff on automobiles and auto parts not compliant with CUSMA.

Trump has already signalled his intent to impose a new global 10% tariff using a different legal authority, indicating that he is not deterred by the Supreme Court’s decision. Section 122 of the U.S. Trade Act permits tariffs to address trade deficits, albeit with limitations on duration and percentage. Furthermore, Trump has announced plans to initiate investigations under Section 301 of the Trade Act, which could lead to additional tariffs targeting countries with perceived unfair trading practices.
Implications for U.S. Businesses
One of the critical unanswered questions following the ruling is whether American businesses that incurred additional costs due to the now-invalidated tariffs will receive refunds. Trump claimed that the U.S. government has amassed substantial revenue from these tariffs, amounting to approximately $164.7 billion, according to the Penn-Wharton Budget Model. Several businesses, including Costco, have already initiated legal action to ensure they are compensated should the tariffs be deemed unlawful.
The coalition “We Pay the Tariffs,” representing small U.S. businesses, is advocating for a streamlined refund process. Executive director Dan Anthony stressed the urgency of returning unlawfully collected tariff payments, arguing that small enterprises cannot afford prolonged bureaucratic delays or costly legal battles to recover their funds.
Why it Matters
The Supreme Court’s ruling introduces a new layer of complexity to an already turbulent trade environment. While it invalidates certain tariffs, the ruling also leaves room for further conflicts and tariff impositions, both domestically and internationally. As Trump explores alternative legal avenues to impose tariffs, businesses and economic analysts alike are left grappling with the uncertainty of future trade relations and the potential financial repercussions for American companies caught in the crossfire. This situation underscores the ongoing volatility in global trade policies and the far-reaching implications for economies on both sides of the border.
