What the Canada-US tariff documents say, and what they leave open for cross-border carriers

Since July, the United States and Canada have each put measures on the other’s goods. On September 8 the American government signed five more proclamations, among them import bans that take effect September 29. I’ve worked from the two governments’ own documents, the Canadian border notice and the filing message from U.S. Customs and Border Protection (CBP), and I name the law firms where I lean on them.

What each government put in writing

A White House fact sheet dated July 20 says the president signed three proclamations under Section 338 of the Tariff Act of 1930, each adding a 50 per cent tariff to a different set of Canadian goods, in response to what it calls Canada’s discriminatory treatment of American products. The same page says the tariffs apply whether or not a good qualifies under the Canada-United States-Mexico Agreement (CUSMA), and that products already subject to Section 232 tariffs are out of scope. It lists trucks and automobiles among the Section 232 goods.

An August 18 proclamation suspended the duties for three days and reset the start to 12:01 a.m. eastern time on August 22, citing advice that Canada had committed to remove the measures at issue. A September 8 proclamation states that Canada reneged on August 21, the suspension lapsed, and the duties took effect, by Washington’s account.

A White House fact sheet of September 8 says five more Section 338 proclamations had been signed, banning certain Canadian products and reworking what the July action covers. Rock salt and cement come out; all-terrain vehicles and more dairy go in. The fact sheet sets September 15 for the scope changes and September 29 for the bans. Both dates have passed, and none of these documents says how either side has applied them since. One ban proclamation says products that will be banned but were imported before September 29 and not yet entered for consumption stay subject to the 50 per cent duty rather than the ban. The fact sheet also says the Section 338 tariffs apply in addition to Section 232 tariffs, which differs from the July page. CBP’s message of September 11 (CSMS #69851916) points both ways at entry. From September 15, filers use headings 9903.03.12, 9903.03.13 and 9903.03.14 for the 50 per cent duty, and the message adds 122 classifications to them. It also sets up headings 9903.03.15 and 9903.03.16 at 0 per cent additional duty, for products that include motor vehicles, medium- and heavy-duty vehicles and parts, aluminum, steel and civil aircraft. Only goods subject to 9903.03.13 can claim 9903.03.15. No additional duty means no Section 338 duty, not duty-free; Section 232 duties are separate. Which heading a given truck or trailer falls under comes down to its tariff classification, and I haven’t reproduced CBP’s list here.

Finance Canada’s August 25 release says Canada suspended negotiations and will match the American tariffs “dollar for dollar, rate for rate”, with counter-tariffs of 15, 25 and 50 per cent from September 8. The American proclamations describe a 50 per cent duty. The CBSA notice says Canada’s goods are drawn from those targeted by both Section 338 and Section 232 tariffs, with each surtax generally corresponding to the U.S. rate, which would account for rates below 50 per cent, though the notice does not say so.

What the border notice requires

The Canada Border Services Agency published Customs Notice 26-23 on September 7. It sets the surtax under the United States Surtax Order (2026), from September 8, at 15, 25 or 50 per cent of the value for duty, and limits it to goods that originate in the United States, which the notice defines as goods eligible to be marked as American under the CUSMA marking regulations. Declarations carry a surtax code by rate, 26186A, 26186B or 26186C, and the amount goes in field 85. The surtax itself cannot be appealed, the notice says, though CBSA determinations can be.

The in-transit exception is narrow. The notice says the surtax does not apply to American goods in transit to Canada on the day it comes into force, September 8, and that this takes in goods already in transit before that day. In transit means bound for Canada, not yet arrived and under the control of a carrier. Finance Canada’s product list states the same carve-out. It is a one-time transitional exception tied to that date, not a standing exemption for loads in a carrier’s hands. The importer has to hold proof, which the notice says may be a bill of lading, report of entry or cargo control documents.

The American measure carried no such provision. Davis Wright Tremaine, a law firm, wrote on August 27 that the Section 338 tariffs have no in-transit provision and do not spare goods qualifying under the trade agreement, so loads crossing when those duties began on August 22 had no equivalent relief. The September 8 motor-vehicle proclamation, effective September 15, says the Section 338 duties apply in addition to Section 232 duties.

Where the sources disagree

Finance Canada puts the American action at $27.6 billion in Canadian goods taxed at 50 per cent, and sets Canada’s own coverage at the same figure for American imports, naming no currency for either. Blakes, a law firm, reports the same figure as C$27.6 billion. Davis Wright Tremaine puts the American measure at roughly $20 billion of Canadian goods a year, and the White House fact sheet of September 8 describes Canada’s tariffs as covering about $20 billion of American exports. Neither figure is reconciled.

Counts differ too. Davis Wright Tremaine says the American proclamations reach 554 eight-digit provisions of the American tariff schedule, and puts Canada’s list at 874 products. Blakes says it runs to more than 600 product classifications. Both firms are describing the same Canadian list.

For freight, and what I’d watch

Canada’s table includes equipment a fleet buys. Tariff item 8716.39.30, trailers and semi-trailers for road tractors or for goods vehicles, is listed at 25 per cent. Fork-lift trucks at 8427.10.10 and 8427.90.00 are listed at 15 per cent.

As I read Customs Notice 26-23, the surtax is the importer’s to pay: the notice is written for importers, asks them to hold proof that goods were in transit, and sets how the amount payable is calculated on commercial importations. A carrier’s exposure then depends on its role. One that imports equipment itself, a trailer at 25 per cent for example, pays it. One hauling someone else’s goods does not, as far as the notice shows, but the proof it accepts includes a bill of lading and cargo control documents, which a carrier would normally hold. My read is that the first thing a cross-border carrier feels is requests for those documents, not a charge of its own. The sources say nothing about how the 50 per cent American duties are changing volumes or lanes, which is the larger commercial question.

The White House fact sheet of September 8 says Canada imposed its tariffs that day and presents the five proclamations as the response. What I’d watch first is which tariff headings trucks and trailers land under in CBP’s list. After that, how each side has applied the September 15 and September 29 dates, and whether any source starts reporting border volumes.