Data & Tariff Disclaimer

Last updated: 2026-10-29. ExportSonar republishes and calculates with public tariff data. This page states where every number comes from, how old it is, what the estimate does not include, and what ExportSonar is not. It states the same boundary as the calculator result card and the API report — not a second, softer version of it.

Not legal, customs or tax advice

Nothing on ExportSonar is legal, customs-brokerage or tax advice, and nothing here creates a professional relationship. Duty estimates are informational. Only US Customs and Border Protection can make a binding determination on a specific shipment, and classification rulings are issued per article; our CBP ruling archive shows how those determinations read. For a decision with money at stake — an entry, a valuation, a penalty exposure — confirm with a licensed customs broker, your own counsel, or CBP directly before you act.

Where the data comes from

• HTS rates and descriptions — the USITC Harmonized Tariff Schedule REST export (hts.usitc.gov). Current table: 23,193 HTS lines across 97 chapters, snapshot generated 2026-10-19T13:27:57Z. Rebuild cadence: 90 days.
• Chapter 99 trade-remedy provisions (Section 301/232 family) — the same USITC export, Chapter 99 range 9900–9999. Current build: 637 eight-digit records from a 2026-10-16T19:19:59Z snapshot. Rebuild cadence: 7 days. Provision labels are derived from the official text rather than from a program column (the export has none), so treat them as derived.
• Section 301/232 origin scope — USITC Chapter 99 General Notes (U.S. notes 20/30/31 and related headings), mapped to 8-digit codes. Rebuild cadence: 30 days.
• Entry fees (MPF/HMF) — Federal Register notices. Rebuild cadence: 180 days.
• AD/CVD cases and orders — Federal Register / ITC publications, rebuilt daily for cases and weekly for orders; CBP CROSS rulings — weekly; UFLPA entity list and EPING notices — weekly.

Every API response carries a data_vintage field naming the build it was served from, and every dataset page links its source. If a build date looks stale to you, it is — say so through the contact page and we will tell you when the next refresh is due.

The coverage boundary — what the headline number excludes

The headline duty figure is the Column 1 General (MFN) rate for the HTS line: the ad valorem percentage, a specific duty per unit, or both. On top of that the calculator shows separate policy layers, and each one is flagged in the result and in the API as included_in_estimate: false. Concretely:

• Section 301 / Section 232 additional duties (Chapter 99 provisions) are surfaced with their provision number, rate and source — but they are not added into the headline estimate. Read them as a preview and add them yourself.
• Preferential / FTA rates (HTS Column 1 Special) are shown as eligibility only: the program codes and what they mean. No preference is applied automatically, because eligibility depends on origin documentation we cannot see.
• Merchandise Processing Fee and Harbor Maintenance Fee are shown as preview lines with their Federal Register source; they are not inside the headline estimate.
• Not modeled at all: AD/CVD rates that apply to your specific exporter or producer (use the AD/CVD screen), tariff-rate-quota fill status and quota allocations, Section 337 exclusion orders, state and local taxes, freight, insurance, currency conversion, and any retroactive rate change made after the build date printed on the page.

The same boundary is restated in policy_layers in the API docs, visible in the calculator result card, and measured line by line against live competitor tools on the accuracy check page.

Estimates, not quotes

Rounding, unit conversions, minimum and maximum duty rules, and the difference between entered value and customs value all move the real number. A compound rate text we cannot parse to machine precision is reported as unparseable rather than guessed — if you see that note, the figure needs a manual lookup against the official schedule.

Your part

Verify before you rely: check the HTS line against the current official schedule, confirm whether a Chapter 99 provision applies to your origin and entry date, and keep your own record of the classification you used. ExportSonar is a fast first look, not the file of record.

Third-party material

Government publications are public data and are republished as-is. Ruling texts and notices are quoted from their sources; trademarks and product names belong to their owners and are used only to identify the material. Links to external sites are provided for verification and do not imply endorsement.

No warranty, and reporting errors

Data is provided without warranty of any kind; the liability limits in the Terms of Service apply. Errors do happen and we want them reported: send the HTS code, your query and what you expected through the contact page — data corrections take priority over feature work.