US Changes Which Canadian Goods Pay the 50% Section 338 Duty from 30 October 2026

Catch-up: the proclamation was signed on 23 October 2026 and applies from 30 October 2026.

What changed

A US presidential proclamation dated 23 October 2026 changes the list of Canadian products subject to the additional 50% ad valorem duty imposed under Proclamation 11048 (Section 338). Annex I, Part A lists 22 HTSUS subheadings that "shall no longer be subject to the additional ad valorem duty of 50 percent". Part B lists 100 subheadings that "shall be subject to" it. Annex II makes the matching changes to U.S. note 51 in subchapter III of Chapter 99 of the HTSUS.

Lines removed include corrugated paper or paperboard boxes (4819.10.00) and plywood sheets not over 6 mm thick (several 4412.33 and 4412.34 lines). Lines added include sweetened cocoa powder (1806.10), many floor-covering lines in Chapter 57 and other goods in Chapters 32 to 95. The annex states that product descriptions are for information only; the HTSUS subheadings set the scope.

The proclamation removes only the 50% Section 338 duty from Part A goods. It states that Section 338 duties "apply in addition to duties imposed pursuant to section 232". Part B does not apply to civil aircraft or parts that meet the criteria of General Note 6 of the HTSUS.

Effective date

The changes apply to goods "entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern time on October 30, 2026."

Who it affects

Canadian exporters and US importers of goods in the listed subheadings, and their customs brokers.

What exporters and importers should do

• Check your HTSUS subheadings against Annex I, Parts A and B.
• Plan for the 50% duty on Part B goods entered from 30 October 2026.
• Check which other duties still apply to Part A goods.
• Send scope questions to US Customs and Border Protection (CBP) and watch for CBP guidance.

Source: The White House, Proclamation of 23 October 2026, with Annex I and Annex II.