On October 29, 2026, CBP published CSMS #70314289, “Further Modifying Section 338 Additional Duties on Certain Goods of Canada.” It gives filing instructions for the October 23 proclamation that changed which Canadian products carry the 50% duty. The changes apply to goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. Eastern on October 30.
What came off
Products of Canada in 22 HTSUS classifications are no longer subject to the 50% duty under heading 9903.03.14. They are 1212.21.00, 3920.20.00, 3923.10.90, 3923.21.00, 4412.33.06, 4412.33.26, 4412.33.32, 4412.33.57, 4412.34.26, 4412.34.32, 4412.34.57, 4811.51.20, 4811.51.40, 4819.10.00, 4819.40.00, 4823.70.00, 4823.90.10, 8418.69.01, 8419.89.95, 8422.30.91, 8422.40.91, and 8433.60.00. In product terms, that is seaweeds and algae, certain plastics, plywood, paper, paperboard and packaging, refrigeration equipment, and machinery.
What went on
100 additional HTSUS classifications are now subject to 9903.03.14. CBP attached a list of every classification subject to Section 338 duties as of October 30, with the new ones in bold. The CSMS does not name the 100 in its text, so the attachment is the place to check. Reports on the proclamation mention valves, carpets, waste products, cocoa powder, acrylic paints, soaps, vinyl flooring, and fiberboard among them.
CBP made no changes to the classifications under 9903.03.12 or 9903.03.13.
The Chapter 99 structure
Headings 9903.03.12, 9903.03.13, and 9903.03.14 each carry a 50% additional duty, depending on which subdivision of U.S. note 51 the goods fall under. Heading 9903.03.15 carries 0% for aluminum, steel, and copper articles and their derivatives, certain vehicles and parts, wood products, semiconductor articles, and patented pharmaceuticals. Heading 9903.03.16 carries 0% for civil aircraft and related goods. As CBP stated in September, only goods under 9903.03.13 can claim 9903.03.15. If your goods are on the 9903.03.14 list and also carry Section 232 duties, ask your broker how the two interact, since the White House says the Section 338 duties apply in addition to Section 232.
The filing rules CBP restated
Goods in headings 9903.03.12 through 9903.03.16 remain subject to antidumping, countervailing, and other duties, taxes, and fees that apply to them.
The additional duty does not apply to goods for which entry is properly claimed under a Chapter 98 provision, with exceptions. Goods entered under subchapter XXIII of Chapter 98 and under subheadings 9802.00.40, 9802.00.50, and 9802.00.60 do pay it. For the 9802.00 subheadings that cover repairs, alterations, and processing abroad, the duty applies to the value of that work. For 9802.00.80, it applies to the value of the article assembled abroad, less the cost or value of the U.S. products in it.
Goods admitted to a foreign trade zone can only be admitted in privileged foreign status, as defined in 19 CFR 146.41, unless they qualify for domestic status under 19 CFR 146.43. They are subject to the ad valorem rate tied to their classification when entered for consumption.
The duties under 9903.03.12 through 9903.03.14 are eligible for drawback. That makes the duty recoverable in principle, but a claim still has to be filed and substantiated.
What the CSMS does not cover
It says nothing about entries made before October 30, and it does not describe in-transit treatment. The effective date turns on the date of entry for consumption or withdrawal from warehouse. Questions on entry filing go to the Trade Remedy Branch at TradeRemedy@cbp.dhs.gov. Filing errors go to your CBP client representative or the ACE Help Desk.
What to do now
Check every Canadian HTSUS line against the attached list, including lines that were out of scope before October 30. For the 22 removed classifications, confirm that 9903.03.14 is no longer on entries from October 30 onward. For the 100 added, confirm it is, and update your quoting and landed cost models.
Look at any Canadian goods sitting in a foreign trade zone or a bonded warehouse. The date they are entered or withdrawn for consumption decides which version of the list applies.
If you use drawback, ask your broker whether these duties fit your claims. Do not assume the duty comes back automatically.
If you want a review of your Canadian entries, reach out to our team.