Methodology & release record

Know what is in the answer.

Source coverage is not the same as calculation coverage.

Research release research-2026-09-07.1

Selected source records checked Sep 7, 2026. This is not a comprehensive legal review or a continuously updated feed.

Inspect the evidence, not just the release date.

The evidence register exposes historical schedule intervals, linked documents, missing snapshots, and review gaps. A source link and a passing test are not professional approval.

Open evidence & release register →

Coverage by workflow

Workflow	Available	Not established by the tool
Historical tariff search	Selected authority matches through April 14, 2026; earlier dates may have no records in the model.	Complete HTS classification, base duty, Section 301 list placement, AD/CVD, or later changes.
Historical comparison	Side-by-side reference matches within the same dated model.	A total landed-cost comparison, sourcing recommendation, or current rate quote.
China IEEPA refunds	Estimation and entry review for the historical China IEEPA period.	Other origins, de minimis/postal calculations, live CAPE acceptance, or a refund award.
Interest	Quarterly rate periods from 2025 Q1 through 2026 Q4.	Actual entitlement, actual deposit date if omitted, or unknown future rates.
Change register	Selected official records, with scope and dates.	Every amendment, stay, exception, or current-law development.

How to use a result

Verify the input against your entry records.
Read the matched rule and its conditions, not just the percentage.
Check the source, effective interval, and coverage notice.
Take unresolved facts to your broker or trade adviser before filing.

Historical model releasehistorical-2026-04-14.1

Corrections and updates

Material rule changes require a source record, implementation review, and regression tests before they enter the calculator. A newly indexed document does not automatically change a rate.

When reporting a discrepancy, include the page address, HTS code, origin, date, expected treatment, and official source. Remove importer identifiers and confidential records.

Report a public-data issue on GitHub ↗

GitHub issues are public. Do not attach entry files or financial information.

Source directory

Data handling & privacy →