Rules version: section232-v1-2026-08-08 — every scan response includes this exact string (result.rulesVersion) so you can tell which ruleset produced your numbers.
Each HTS code you enter is normalized to 4-10 digits, then matched at the chapter (first 2 digits) and heading (first 4 digits) level against two data sets: the primary Section 232 metal chapters (steel, aluminum, copper) and the 14 proposed BIS derivative articles from the Aug 6 2026 Federal Register notice. This is a heading-level match, not a full 10-digit tariff classification.
Every TariffWatch scan response includes both the rulesVersion string and the specific matched-heading array (result.matches[]), so you can independently confirm what the calculator did. To verify a Section 232 flag, look up the HTS heading on theUSITC Harmonized Tariff Schedule and confirm the chapter is 72, 73, 74, or 76. To verify a BIS-14 flag, look up the same heading in the Aug 6 2026 Federal Register notice and confirm it appears in the 14 proposed derivative-article annex. If our result and your manual lookup disagree, email a screenshot to hello@citationsafe.com — corrections land on /corrections with the affected rule and fix, not in a support-ticket black box.
The Apr 6 2026 Presidential Proclamation established that derivative articles whose Section 232 metal content by value is 15% or less are exempt from the Section 232 add-on rate on the non-metal portion of the customs value. TariffWatch does not automatically claim the exemption for you — the exemption requires a specific attestation from the importer of record, and the calculator has no way to verify your composition data. What it does do is surface the exemption as a checkbox on the exposure form: if you tick it, we recompute the estimate against the non-metal portion only, and the result carries a exemptionAttested=true flag in the response so you can see exactly what the estimate assumed. If you leave the box unticked, the calculator assumes no exemption and estimates full-customs-value exposure — the safer default.
The 2018-onward Section 301 tariffs on China imports (Lists 1 through 4A, published by USTR) stack additively with Section 232 for goods that are both from China and a Section 232 metal article. TariffWatch does not currently calculate Section 301 exposure — the ruleset would need a separate section301-v... version string and USTR's docket instead of BIS's — so a scan against a Chinese-origin steel article today reports Section 232 exposure only and explicitly notes the Section 301 stack in the result UI. If you need combined Section 232 + Section 301 exposure, your customs broker's classification system is the right place today.
The BIS Section 232 product-specific exclusion-request process under 15 CFR § 705.5 was terminated by Presidential Proclamation 10895 (steel) and Presidential Proclamation 10896 (aluminum), both dated February 10, 2025. The BIS Section 232 Exclusions Portal at 232exclusions.commerce.gov is READ-ONLY as of that date and no new exclusion requests can be filed there.
The current live BIS mechanism for importers affected by the Aug 6 2026 Federal Register notice (FR 2026-15961, proposing to ADD 14 derivative articles to Section 232 tariff coverage) is filing a public inclusion-rebuttal comment on the regulations.gov docket under the 5 U.S.C. § 553(c) notice-and-comment rulemaking framework. We draft product-specific, HTSUS-precise 10-section rebuttal comments arguing why a proposed article should NOT be added to Section 232 coverage — see the inclusion-rebuttal comment templates (free DIY) or the $99 concierge drafting service per template page. 48 business-hour turnaround from paid intake to submitted comment.
section232-v1-2026-08-08 is the only rules version shipped to date. If the underlying rate tables or BIS-14 article list change, the version string changes with them and this page is updated to match.