Canada's dollar-for-dollar tariffs on $27.6 billion of U.S. goods take effect

Canada's retaliatory surtaxes on United States goods came into force at 12:01 a.m. on 8 September 2026. The Department of Finance list covers 874 tariff lines and about C$27.6 billion (US$19.9 billion) of American imports. Rates are 15, 25 or 50 percent. Each rate is meant to match the U.S. duty on the corresponding Canadian product under Section 338 and Section 232.

Prime Minister Mark Carney announced the package after talks with Washington collapsed and President Donald Trump imposed a 50 percent tariff on US$20 billion of Canadian goods from 22 August. Ottawa said it would answer dollar for dollar. The product schedule was published on 25 August. Goods already in transit to Canada on the effective date are exempt. The Canada Border Services Agency will administer the rest through customs notices.

The Finance Department split the lines by rate. Twenty-one items carry 15 percent. Four hundred and forty-nine carry 25 percent. Four hundred and four carry 50 percent. Steel and aluminium account for more than 300 of the 874 lines. Almost all of Chapter 72, raw and semi-finished steel, and Chapter 73, fabricated steel articles including tube, pipe, structural shapes and fasteners, move to 50 percent. That doubles the counter-tariff those metals already faced. Existing 25 percent surtaxes on U.S. motor vehicles stay in place as a separate measure.

Dairy is one of the sharpest new hits. A 50 percent tariff now applies to milk and cream, including concentrated and sweetened varieties and powders, and to whey and several milk and whey protein products. Fresh cheese and curd, including grated, powdered and processed varieties, take 25 percent. The list names Camembert, Brie, blue cheese, cheddar, mozzarella, Swiss, Gruyère, Havarti and Parmesan. Under the United States-Mexico-Canada Agreement, U.S. dairy enters tariff-free until quota ceilings. Over-quota rates already ran above 200 percent. The new 50 percent duty applies both below and above those quotas.

Seafood takes 25 percent across a wide range of fisheries products. Wood products sit at 25 to 50 percent: sawn or chipped wood, plywood, veneered panels, wood pulp, paper and paperboard, boxes, and toilet and similar paper. Softwood lumber under heading 4407 is at 25 percent. Plywood and laminated veneer under 4412 sit at 50 percent. Furniture, domestic seating, wooden, plastic and metal pieces and parts, is taxed at 25 to 50 percent depending on the heading. Clothing joins the 50 percent band. Appliances, agricultural equipment and electronics are on the list because those Canadian sectors were among the hardest hit by the U.S. duties.

The RV Industry Association reviewed finished-unit codes for motorhomes, vehicle bodies, slide-in campers and camping trailers after the 874-line file appeared. Component chapters that feed assembly plants, including fasteners under 7318, are covered. Importers who rely on U.S. screws, bolts and washers now pay the 50 percent steel rate even when the finished good is assembled in Canada.

Ottawa framed the list as relief for the same sectors Washington targeted. The political cost sits on both sides of the border. Canadian households will pay more for U.S. cheese, appliances and paper. American mills and dairies lose a neighbour market they have used for decades. CUSMA-originating goods still have an exemption path on some older measures, but the new September list is written to match the U.S. Section 338 rates rather than to preserve the old free-trade pattern.

The tariff war with Canada and Mexico has been running since 2025. Tuesday's step is the first time Ottawa has put a full, published, product-level schedule of this size into force after the latest U.S. round. Finance officials said further administrative guidance would follow on the CBSA site. Until then, brokers are working from the 25 August backgrounder and the 874-line annex.

Analysts tracking North American freight have already flagged a timing wrinkle. Because goods in transit on 8 September are exempt, some shippers pushed cargo across the border in the days before the deadline. After that window closes, the surtax attaches at the border. There is no staged phase-in.

What happens next depends on whether Washington treats the Canadian list as a bargaining chip or as a reason to add another round. Carney has said the rates stay until the U.S. duties come off. Trump has separately threatened action against Bombardier aircraft sales, which would pull a Canadian export champion into the same fight. For now the legal fact is simpler. At one minute past midnight on 8 September, 874 American product lines began paying Canadian retaliatory duty.