US widens 50% tariffs on Canadian imports

On Tuesday morning, the United States began imposing 50 percent tariffs on a wide range of Canadian imports, impacting 110 tariff items while removing ten others. This adjustment took effect at 12.01am Eastern Time on September 15, as part of a package of measures signed by President Donald Trump on September 8 in response to Canada's retaliatory tariffs on US goods.

The White House stated the revisions aimed to "offset the burden to US commerce while better serving the public interest". Products that had been exempt from the 50 percent tariff list, such as rock salt, Portland cement, pure sugars, tissue and towel stock, paper bed sheets, refined lead, low-voltage switchgear and fishing rod parts, were now subject to the levy.

Simultaneously, the 10 products previously under the 50 percent tariff were excluded, resulting in a roughly unchanged overall value of affected US trade. RBC Economics estimated that the 10 removed products were worth about US$1.73 billion in 2025 US imports, compared to around US$1.85 billion for the products added. The administration's decision to combine these measures reflects a strategic approach to considering the impact on US buyers and supply chains.

The tariff adjustments were made under Section 338 of the Tariff Act of 1930, enabling the president to respond to perceived discriminatory trade practices by other nations. This particular adjustment followed Canada's initiation of counter-tariffs of 15, 25 or 50 percent on specified US-origin goods, covering Canadian exports valued at C$27.6 billion.

Canada defended its actions, asserting they were a balanced response to earlier US duties on dairy, alcoholic beverages, and motor vehicles, which it deemed discriminatory. The original Section 338 tariffs came into force on August 22, imposing additional 50 percent duties on certain dairy, alcohol, and motor vehicle products, while exempting energy, potash, critical minerals, and goods under national-security tariffs.

Tuesday's tariff changes do not reduce the statutory 50 percent rate; instead, they modify the product categories subject to the duty and adjust how duties stack for some categories. These changes come as a separate set of restrictions, scheduled to begin on September 29, will further restrict Canadian alcoholic beverages, dairy products, and motorcycles from entering the US market.