ProclamationUnited StatesIn force, not yet used

Section 338 proclamations on Canada (Proclamations 11046, 11047, 11048 (Jul 20, 2026); 11056 (Aug 18, 2026); five proclamations of Sep 8, 2026)

The first express use of Section 338 of the Tariff Act of 1930 to impose tariffs. Three proclamations of 20 July 2026 set 50% tariffs on Canadian goods, citing Canada's treatment of US alcohol, dairy and motor vehicles; goods that qualify under USMCA are not exempt. The tariffs were due on 19 August; Proclamation 11056 of 18 August suspended them until the end of 21 August, and they took effect on 22 August. Five proclamations of 8 September 2026 changed the product lists from 15 September and banned some imports from 29 September. A proclamation of 23 October changed the motor-vehicle list again from 30 October, removing 22 tariff lines and adding 100, with the 50% rate unchanged. The White House fact sheet gives no dollar figure for the goods covered; Global Trade Alert puts them at US$17.7 billion, and Canada's Department of Finance at $27.6 billion (Canadian).

Stages

Passing a law is not the same as switching it on, and switching it on is not the same as using it. Each stage is dated where known.

1. Announced 20 July 2026
   Three Section 338 proclamations impose 50% tariffs on about US$20B of Canadian goods, including USMCA-compliant goods: the first known use of Section 338 to impose tariffs
2. In force 22 August 2026
   US Section 338 tariffs of 50% on Canadian goods take effect; Carney says the US 'asked too much and offered too little'
3. Amended 8 September 2026
   Trump signs five Section 338 proclamations: bans on some Canadian alcohol, dairy and motorcycles from 29 Sep and a revised tariff list from 15 Sep
4. Amended 23 October 2026
   Trump signs a proclamation changing the list of Canadian goods under the 50% Section 338 tariffs, effective 30 October: 22 tariff lines out (thin hardwood plywood, some paper and plastic packaging, machinery), 100 in (carpets, valves, waste, cocoa powder, thin MDF and other goods)

Events

• 23 October 2026Trump signs a proclamation changing the list of Canadian goods under the 50% Section 338 tariffs, effective 30 October: 22 tariff lines out (thin hardwood plywood, some paper and plastic packaging, machinery), 100 in (carpets, valves, waste, cocoa powder, thin MDF and other goods)ActionTariff actionUnited States5 sources
• 29 September 2026US import bans on certain Canadian dairy products, molasses, alcoholic beverages and motorcycles take effectActionTariff actionUnited States8 sources
• 29 September 2026As US import bans take effect, Carney rules out further trade pressure and says Canada 'stands ready to negotiate in good faith'; LeBlanc says Canada won't apologizeStatementStatementCanada2 sources
• 15 September 2026Changes to the list of Canadian products under the 50% Section 338 tariffs take effectActionTariff actionUnited States2 sources
• 8 September 2026Canadian counter-tariffs take effect on C$27.6B of US goods (about US$20B), matching the US Section 338 tariffsActionTariff actionCanada3 sources
• 8 September 2026Trump signs five Section 338 proclamations: bans on some Canadian alcohol, dairy and motorcycles from 29 Sep and a revised tariff list from 15 SepActionTariff actionUnited States4 sources
• 22 August 2026US Section 338 tariffs of 50% on Canadian goods take effect; Carney says the US 'asked too much and offered too little'ActionTariff actionUnited States2 sources
• 18 August 2026Trump announces a tentative deal with Canada, 'subject to the finalization of documents', and suspends the Section 338 tariffs until the end of 21 AugustActionTariff actionUnited States3 sources
• 20 July 2026Three Section 338 proclamations impose 50% tariffs on about US$20B of Canadian goods, including USMCA-compliant goods: the first known use of Section 338 to impose tariffsActionTariff actionUnited States6 sources
• 4 March 2025Provincial liquor boards, including Ontario's LCBO and Quebec's SAQ, pull US alcohol from their shelvesActionTariff actionCanada3 sources