MFN is the base layer
Read the current HTS General field first. Free, simple ad-valorem, specific, and simple compound duties retain their structure; unit components require quantity or weight.
Do not add every percentage: test exclusions, exemptions, and caps first
A reliable duty stack first asks whether a layer applies, then calculates its amount. This page describes the verified forced-labor Section 301 rules only; legacy China Section 301, AD/CVD, quotas, and other Chapter 99 instructions still require separate resolution.
Resolve a specific HTS and originThe 10% and 12.5% tiers generally add to MFN
Seventeen economies use the 10% tier and the other investigated economies generally use 12.5%, but Section 232, preference, and Annex questions are tested first.
The EU, Taiwan, Japan, Korea, and Switzerland use net-of-MFN caps
MFN plus this layer is capped at 10% for the EU and Taiwan and 12.5% for Japan, Korea, and Switzerland. If MFN already meets or exceeds the cap, this layer is zero—not negative.
Section 232 coverage excludes this origin layer
Articles and parts already subject to Section 232 tariffs do not also receive this new origin-based forced-labor Section 301 layer. The separate Section 232 duty still has to be calculated.
USMCA and CAFTA-DR carve-outs depend on actual Free special treatment
Canada/Mexico goods must qualify under USMCA; the CAFTA-DR carve-out is limited to qualifying textile and apparel. An origin name alone is not enough.
A computable scenario is not evidence-complete
Callers may mark layers not applicable for scenario planning. A source-backed final total appears only when official sources or broker confirmation support every decisive layer.
AD/CVD cannot be safely added or excluded from HTS alone
HTS is a reference aid. Written scope, specifications, material, and use control coverage, so the final total must stay partial until reviewed.
Recommended resolution order
- 1Confirm the HTS code, raw base-rate field, US customs value, and measurements required by unit duties.
- 2Use a timezone-qualified entry instant to test effective dates and the short transit exception.
- 3Test Section 232, USMCA, CAFTA-DR, and Annex carve-outs.
- 4Apply the flat tier or net-of-MFN cap.
- 5Separately review legacy China Section 301, AD/CVD, quota, safeguard, and other Chapter 99 layers.
- 6Separate a computable modeled scenario from an evidence-complete result; publish a source-backed final rate only for the latter.