Who Pays Canada’s Tariffs Depends on More Than Border Crossings

The roughly $20 billion attached to Canada’s new retaliatory tariffs measures goods covered, not a bill handed to American producers. The package, effective September 8, 2026, covers C$27.6 billion in imports, approximately US$19.9 billion, with rates of 15%, 25% and 50%. Those distinctions matter before anyone starts multiplying tariffs by the number of times a component crosses the border. The immediate question is which shipments actually incur duties, and who can escape the resulting cost. (canada.ca¹)

Washington’s response also requires a calendar. Announced bans on selected Canadian dairy products, alcoholic beverages and motorcycles are scheduled for September 29; additional 50% automotive restrictions discussed for next year remain threats. They cannot explain customs charges already incurred this week. I would assess this escalation by the duties that survive exemptions and the alternatives available to each buyer, rather than by the nationality printed on a finished product. (apnews.com³)

Start with the customs bill. Canada assesses its surtax on customs value, generally the transaction price with prescribed adjustments, converted into Canadian dollars using the applicable exchange rate when direct shipment begins. The aggregate C$27.6 billion announcement does not specify its underlying trade-data reference period, so it should not be mistaken for a forecast of this year’s taxable purchases. Shipment values, tariff rates and relief determine collections. (cbsa-asfc.gc.ca⁴)

Nor does dispatch from an American warehouse necessarily make something American. Rules of origin determine a good’s economic nationality under the applicable customs test. For this surtax, Canada uses its U.S.-origin marking rules. Shipping a product through another country does not by itself remove liability. Conversely, another crossing need not create another tax: specified repair-and-return movements are exempt. (cbsa-asfc.gc.ca⁵)

Refunds can interrupt the accumulation, too. Duty drawback returns qualifying duties after goods are exported; duties relief can defer payment on qualifying processing trade. Canada’s rules under the United States–Mexico–Canada Agreement distinguish originating inputs from non-originating ones, with restrictions applying to certain non-originating goods processed for export within the region. A refund entitlement also needs supporting records. I would count completed refunds separately from money a business is still waiting to recover. (cbsa-asfc.gc.ca⁶)

Dairy provides a useful test. Canada’s September schedule puts a 25% surtax on listed U.S. mozzarella imports. Consider two illustrative routes: American cheese shipped to a Canadian grocer, and American cheese shipped to a licensed Canadian processor for incorporation into food that will be exported. The first is exposed absent other relief. The second can avoid the Canadian surtax if imported under a qualifying Import for Re-Export permit and all conditions are met. More movement can therefore produce less Canadian tariff liability. This is a rule-based comparison, not a reconstruction of two actual consignments. (canada.ca⁷)

That exemption does not make sourcing effortless. For the program’s raw-milk and cream route, Canada requires recognized American milk sources, licensed haulers, shipment documentation and eligible processing establishments. These requirements narrow the immediately usable supplier pool. They do not establish a universal switching delay: a processor with another approved source faces a different problem from one that must qualify a replacement. And exemption on entry into Canada says nothing by itself about treatment when the finished food enters the United States. (inspection.canada.ca)

Aircraft illustrate the same distinction between an integrated production route and proven cumulative taxation. Honeywell makes engines for Bombardier’s Challenger jets in Phoenix; Bombardier identifies Montréal as the Challenger 3500’s assembly and completion location. An engine incorporated into a jet delivered to an American customer thus returns inside a higher-value product. That route establishes American participation in Canadian production. It does not establish two tariff payments. Trump’s threatened Bombardier sales ban would also need to be distinguished from an enacted duty on either shipment. (apnews.com)

Replacing an aircraft input is plainly different from choosing another brand of office supplies. For replacement and modification parts, the Federal Aviation Administration requires demonstrated compliance with airworthiness standards through testing and computations or qualifying identicality. I infer that an unapproved substitute cannot provide immediate relief, although an existing approved alternative might. Those rules justify caution about easy substitution, not an invented claim that every supplier change takes six months. (faa.gov¹¹)

Buyers still have bargaining tools. Boeing’s January 2026 commercial fixed-price terms generally require signed written amendments, except where the contract authorizes otherwise. Such terms can resist a supplier’s unilateral invoice increase. But in an illustrative transaction, holding an invoice at C$100 leaves the buyer with C$125 in goods-plus-surtax costs if customs value is C$100 and the buyer separately owes a 25% duty. Exporter absorption requires an actual concession or contractual responsibility for that charge. A fixed price alone cannot supply either. (boeingsuppliers.com¹²)

The claim that exporters will cut prices rather than lose customers deserves serious weight. Research by Alberto Cavallo, Gita Gopinath, Brent Neiman and Jenny Tang found that American exporters reduced prices on products hit by earlier foreign retaliation. Yet their import-side evidence found tariffs almost fully reflected in costs paid by U.S. importers. Differences between affected and unaffected retail prices were generally modest, consistent with retailers sacrificing margins. Stable shelf prices therefore cannot tell us that foreign producers paid the tax. (bostonfed.org¹³)

I take that evidence as a warning against assigning one national winner. For shipments with unrelieved duties and few usable substitutes, domestic business losses are the more credible near-term expectation. Where buyers can replace a product, exporters have greater reason to concede price or lose orders. Neither result measures this September’s outcomes: historical estimates cannot substitute for current invoices, margins and matched comparisons with unaffected products. (bostonfed.org¹³)

Alcohol adds a complication that crossing counts miss entirely. In documenting a 2020 investment, Heaven Hill described Black Velvet whisky moving by rail from Lethbridge, Alberta, to Bardstown, Kentucky, then by truck to its bottling facility. That documented route places American processing downstream of Canadian distillation. A restriction interrupting such a flow would expose American bottling operations as well as the Canadian producer; it would not need repeated border taxation to do so. The historical route is evidence of integration, not proof of a particular September shipment’s treatment. (heavenhill.com¹⁴)

The public material establishes schedules, exemptions and production routes, but I could not verify linked shipment histories showing successive net duties, completed refunds and resulting margins for these products. That prevents an honest estimate of who bears most of the escalation’s total losses. It does not prevent a judgment: counting crossings exaggerates some exposures, while assuming foreign suppliers finance the remaining duties understates the danger to domestic manufacturers.

Lost access must also be counted separately from tariff payments. The Distilled Spirits Council, using U.S. trade data, reports that American spirits exports to Canada fell from US$203 million in March–December 2024 to US$60 million in the corresponding 2025 period following provincial sales bans. Those figures measure sales, not profits or tariff absorption. But they demonstrate how severely a supplier can be hurt without a tariff accumulating along its production route: exports excluding Canada rose 2.5% over the full year. (distilledspirits.org¹⁵)