US Tariffs Changed 50+ Times Since 2025. Is Your Landed-Cost Math Still Right?

CBP Quietly Rewrote Four Tariff Exclusions. Your Landed Costs May Already Be Wrong.

For global sellers importing into the United States, the cost of bringing a product to market is a moving target. A recent update from U.S. Customs and Border Protection (CBP) shows just how fast it can move.

On September 22, 2026, CBP issued guidance (CSMS #69990649) on conforming amendments to four Section 301 China product exclusions, following changes to the Harmonized Tariff Schedule of the United States (HTSUS) that took effect July 1, 2026. The amendments update the statistical reporting numbers importers must use when claiming exclusions under HTSUS 9903.88.69 — and CBP's Automated Commercial Environment (ACE) began accepting the new numbers on September 23. The underlying changes were published by the Office of the U.S. Trade Representative in the Federal Register on September 2, 2026.

When tariff classifications change.

For example, certain goods previously reported under 8413.91.9065, 8413.91.9085, or 8413.91.9096 now fall under different statistical reporting numbers, as do goods previously reported under 3926.90.9910.

Technical? Yes. Inconsequential? No. Importers that kept using the old numbers between July 1 and September 22, 2026 may have paid Section 301 duties they didn't owe. CBP encourages affected importers to seek refunds through a Post Summary Correction or a protest, within the applicable filing windows.

Why this matters for global sellers

For an ecommerce business with hundreds or thousands of SKUs, tariff compliance is not a one-time calculation. A single change — to a classification, a duty rate, or an exclusion — can ripple across the correct HTSUS classification, the total duty rate applied, exclusion eligibility, entry filing requirements, landed-cost assumptions, duties already paid, and refunds that may be recoverable.

And this isn't only about China. Earlier this year, CBP implemented additional tariffs on certain Brazilian products. In July, new Section 301 duties tied to forced-labor findings took effect across 60 economies — an additional 12.5% on top of existing rates for most, bringing the aggregate Section 301 rate on Chinese goods to 37.5% — replacing the expiring Section 122 tariffs.

The result: estimating import costs from a single tariff rate is no longer enough.

The challenge of keeping landed costs accurate

Landed cost goes well beyond purchase price and freight. Duties, fees, and other import charges can materially change what it actually costs to get a product to the customer — and every rule change forces businesses to revisit classifications and recalculate.

For large catalogs, tracking these changes market by market, by hand, doesn't scale.

What sellers can do about it

1. Classify once, review on every change. Keep an HTSUS record for each SKU — with the reasoning behind it — and re-verify whenever CBP or USTR issues an update.
2. Track duties per SKU, per origin, per channel. One blended rate hides the SKUs that are bleeding margin.
3. Reconcile estimate vs. actual after every shipment. If the duty bill keeps differing from the forecast, the model — not the shipment — is the problem.
4. Set a margin alert. Flag any SKU the moment its landed cost crosses a set share of its selling price, instead of discovering it at quarter-end.
5. Put compliance dates on a calendar. Exclusion expiries, PSC and protest windows, ACE update dates — diarise them like tax deadlines.

How technology can help

This is where compliance technology earns its keep. Gloco helps global sellers assess the compliance considerations tied to their products — tariffs, customs duties, licensing, and IP risks. Sellers can submit a product link and use Gloco's AI-powered platform to surface the relevant requirements, calculate customs duties, and prepare documentation for expansion into the US and other markets.

The platform also provides ongoing monitoring and alerts, tracking changing laws and compliance deadlines — so businesses aren't relying on a one-time assessment in a world where the rules rewrite themselves.

Because in this environment, knowing today's tariff is only half the job. Keeping up with tomorrow's changes is the other half.