Tariff Watch: Section 338 Escalates to Outright Bans, 50% Duty List Revised, CBP Changes Copper Rules

This week’s Tariff Watch covers new Section 338 import bans on certain Canadian goods, revisions to the 50% tariff list, new CBP copper reporting requirements, and other trade developments affecting importers and supply chains.

  • September 15, 2026
  • J.M. Rodgers Team
  • Reading Time: 4 minutes
Home » Tariff Watch: Section 338 Escalates to Outright Bans, 50% Duty List Revised, CBP Changes Copper Rules
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Welcome to this week’s edition of Tariff Watch, the ongoing series from J.M. Rodgers designed to keep busy importers, manufacturers, and supply chain leaders ahead of changing US trade policy. The first full week of September 2026 saw major escalations to the Section 338 tariffs on Canadian goods, while other announcements impacted copper and beef imports.

Here’s what you need to know this week:

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What’s New

  • White House announces bans on some Canadian goods: Following last month’s implementation of 50% tariffs on a broad range of Canadian goods, President Donald Trump signed five new proclamations on September 8, instituting outright bans on certain dairy, alcoholic beverage, and motor vehicle imports from Canada. As with the 50% tariffs, the administration invoked Section 338 of the Tariff Act of 1930 to impose the bans, which go into effect on September 29.
  • Admin adds and removes goods from Section 338: In addition to the import bans, the proclamations signed September 8 also mandate adding or removing specific Canadian products from the Section 338 50% tariffs. The Modified Alcohol Tariff Proclamation adds cheese products, leather goods, and motorboats to the 50% duty list, while removing whiskies and liqueurs in containers over four liters. Meanwhile, the Modified Motor Vehicle Tariff Proclamation adds products beyond automobiles to the duty list, including construction materials, furniture, lamps, and light bulbs, while removing salt, toilet paper stock, and similar paper pulp products. These changes take effect on Tuesday of this week, September 15.
  • CBP changes rules for copper imports: US Customs and Border Protection (CBP) announced that on Monday, September 14, it will begin rejecting Automated Commercial Environment (ACE) entry summaries for copper imports missing the required primary country of smelt and country of cast information. ACE will now issue a fatal F794 error when the required Type 12 record is not submitted for the affected HTSUS classifications. These changes have been expected since an April 2 presidential proclamation directing CBP to increase security on aluminum, steel, and copper imports.

Who’s Impacted

The rapidly escalating US-Canada trade war grabs most of the headlines, but this week’s news affects a wide spectrum of the North American supply chain. Here’s who’s impacted the most this week:

  • Businesses that have depended on imports of Canadian dairy, alcohol, and motor vehicles now face a complete prohibition of these goods by the end of the month.
  • US companies that have relied on exports to Canada now see their products subject to tariffs of up to 50%, as Prime Minister Mark Carney formally implemented retaliatory duties last Tuesday, September 8.
  • Filers importing specific copper articles must ensure their systems transmit the required Type 12 record to avoid immediate ACE rejection beginning this week.
  • Companies importing lean beef trimmings have expanded opportunities to bring in goods under a new 300,000-metric-ton adjustment to the US’s tariff-rate quota (TRQ), which recently went into effect and will remain available through November 30, or until the quota fills.

What We’re Seeing

Although September has already been a tumultuous month, dedicated supply chain leaders are finding ways to protect their margins. Here’s what we’re seeing:

  • After the White House upgraded some Section 338 tariffs to full-fledged bans on specific Canadian goods last week, more and more affected businesses are pursuing alternative global sourcing.
  • Compliance managers and customs brokers spent much of last week auditing their data feeds to ensure the new copper smelt and cast origin details are correctly populated before the hard rejections start on Monday.
  • US exporters are actively reviewing the Canada Border Services Agency (CBSA) guidance following the September 8 launch of Canada’s retaliatory tariffs, looking for any possible exclusions or other relief.

What We’re Monitoring

The J.M. Rodgers team is keeping a close watch on these developing and ongoing stories:

  • We’re parsing the five proclamations signed by President Trump last week that go into effect on Tuesday to fully understand the revised scope of the 50% Section 338 duties on Canada. While the proclamations clarify that Section 232 tariffs still apply, resulting in tariffs of up to 75% on specific goods, removing some staples from the duty list will be a relief for US importers.
  • Despite the back-and-forth escalations on both sides of the border, multiple news outlets report that US and Canadian officials are still working behind the scenes to reach a new trade deal. We’re keeping in close contact with our sources to gauge the progress of these discussions.
  • CBP plans to deploy changes to the Entry Type 13 (ET13) error code for US mail processing in the ACE production environment next week, on September 22. We’ve been trying out the changes in the ACE Certification (CERT) test environment to catch any filing or error-handling issues early.
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Sources:

  • White House Ups the Ante with Section 338 Import Bans, JD Supra
  • President Trump Escalates Section 338 Actions, Troutman Pepper Locke
  • Copper Additional Smelt and Cast Country Detail Error Code Update, CBP
  • Trade War “Will Come at Cost” as Canada Strikes Back on Tariffs, BBC
  • Further Ensuring Affordable Beef for the American Consumer, WhiteHouse.gov
  • Cargo Release Condition Codes Documents Have Been Posted, CBP