Canadian Fertilizer Exports and U.S. Section 338 Tariffs: 2026 Status & Outlook

01Current status

The Section 338 measures are product-specific, not country-wide. On 20 July 2026, the White House issued three proclamations, each responding to an alleged Canadian discrimination against U.S. commerce involving dairy, alcoholic beverages or motor-vehicle trade measures.¹ Duty coverage is defined by the specific HTSUS lines in the annexes—not by a headline description of the sector.

That distinction matters because the proclamation concerning motor vehicles contains a broader list of goods, while products already subject to Section 232 duties are excluded. Market participants should therefore check the shipment’s exact HTSUS classification against the operative annexes.

Fertilizer products do not appear in the current lists. Potash is expressly identified as excluded, together with energy, products subject to Section 232 duties and certain other goods such as fish and critical minerals.¹ Urea, MAP, UAN and related fertilizer inputs such as sulfur and sulfuric acid are not listed in the annexes reviewed for this article.³ Canadian fertilizer shipments into the United States are therefore not subject to the new 50% Section 338 duty under the schedule in force as of 23 August 2026.

02Why the distinction matters

In an environment of rapid policy change, general headlines often obscure product-level treatment. The Section 338 duties apply only to listed HTSUS classifications, and they apply regardless of USMCA status: preferential origin treatment does not shield a product once it is named in a Section 338 annex.⁴

The reverse also holds. Products that are not listed remain outside the measure. Correct HTSUS classification, verification of origin documentation and continuous monitoring of the operative annexes are the reliable basis for commercial decisions.

03The broader landscape continues to shift

While fertilizers are currently outside the new 50% duties, the surrounding tariff environment has been unusually fluid. The duties were originally scheduled for 19 August 2026. On 18 August, the White House suspended them for three days amid negotiations, moving the effective time to 12:01 a.m. Eastern on 22 August 2026.² Multiple legal authorities have been used and adjusted in recent months. What is accurate today can require re-verification tomorrow.

For market participants, this creates two practical realities:

• Current exclusions should not be treated as permanent. Future proclamations, annex amendments or related actions could alter the treatment of specific fertilizer lines.
• Price formation continues to be driven primarily by fundamentals, including natural-gas markets in Europe and other major producing regions, rather than by these particular tariff measures.

04Outlook and practical takeaways

Canadian fertilizer exports into the United States retain a structural advantage under the rules as they stand today. That advantage supports continuity of supply for U.S. buyers and preserves commercial pathways for Canadian producers and intermediaries.

However, the environment rewards discipline. Parties structuring fertilizer transactions should:

1. Confirm the exact HTSUS classification of each product against the current Section 338 annexes before shipment or contracting.
2. Maintain clear origin and documentation standards.
3. Build flexibility into commercial arrangements where possible, given the demonstrated capacity for rapid schedule changes.
4. Continue monitoring both U.S. and Canadian measures as the broader relationship evolves.

05The Twenty Arms view

At Twenty Arms, we structure and facilitate international commodity transactions with an emphasis on verification, process discipline and clear documentation. In periods of policy volatility, those fundamentals become even more valuable. Reliable counterparties, accurate classification and transparent commercial structures reduce execution risk when the external environment is uncertain.

The current treatment of fertilizers is welcome and commercially significant. It is also a reminder that, in today’s trade landscape, the difference between assumption and verification can be material. We will continue to track developments closely and support clients with the precision the market requires.

References

1. The White House, “Fact Sheet: President Donald J. Trump Imposes Additional Tariffs on Canada,” 20 July 2026. Primary summary of the three proclamations, USMCA treatment and named exclusions.
2. The White House, “Temporary Suspension of Additional Duties…,” 18 August 2026. Primary source changing the effective date to 22 August 2026.
3. Norton Rose Fulbright, “Smoke or fire?” July 2026. Legal advisory on annex coverage and exclusions.
4. Holland & Knight, “50 Percent Opening Bid,” 29 July 2026. Legal advisory on Section 338 and USMCA treatment.
5. GHY International, “U.S. Imposes 50% Section 338 Tariffs on Canadian Imports.” Trade-compliance update and implementation timeline.
6. White & Case, “Trump administration imposes 50% tariffs on certain Canadian products in first use of Section 338.” Background on the legal authority and product scope.