Canada doubled its steel and aluminum surtax to 50% on Sept. 8, 2026 — what importers need to do now

# What happened

# Why this matters to importers The same tariff heading can now sit in either rate bucket depending on the specific good. An HS number that was assigned correctly last month may land in a different bucket now. That means a single misclassification does more than change duty on one shipment — it repeats on every entry using that classification until it's corrected.

CBSA also made this a live rate change, affecting shipments already en route unless the importer can prove the goods were in transit before Sept. 8 using a bill of lading, cargo-control document, or similar evidence tied to legacy code 25095A.

# The new CARM codes and math CBSA replaced two surtax codes with four new codes for CARM declarations:

• 26187A and 26187C — aluminum and steel at 25%
• 26187B and 26187D — aluminum and steel at 50%

# Why CBSA changed the surtax CBSA's update is a direct response to the United States imposing new Section 338 tariffs on a range of Canadian goods in August 2026. This update is the fourth amendment to Customs Notice 25-11 since March 2025, showing a pattern of iterative changes rather than a single, one-off action.

# Immediate compliance checklist (practical steps)

• Audit classifications for affected HS headings now. Don't assume prior classifications still map to the same surtax bucket.
• Update CARM declarations to use the correct new code for each entry. A paperwork error becomes a tax error if the code is wrong.
• Gather and preserve transit documentation for shipments moving before Sept. 8 to claim the 25% grandfathered rate under legacy code 25095A.
• Recalculate landed costs where surtax exposure exists, including MFN duty, any antidumping duty, surtax, and GST to see the real increase in landed cost.

# What to expect next The change follows a pattern of frequent tariff and surtax amendments. Trade teams should plan for more updates rather than treating this as a one-time adjustment. Systems and processes that check the current schedule and codes at the time of accounting, rather than relying on static files, will reduce repeated errors.

# Tools and operational notes Content in the original notice highlights the importance of currency: knowing which schedule a tariff number sits in today is what matters. The notice also shows concrete worked examples illustrating how the surtax stacks with other duties and taxes, which can be used to validate internal landed-cost calculations.

# Bottom line This is a live change with immediate cash implications. Confirm the correct CARM code, validate HS classifications against the new schedules, secure proof for any in-transit shipments, and rerun landed-cost math across affected product lines. The cost of delay or error is recurring and compounds across multiple entries.