Methodology — sources and verification

Every number this site and its calculators surface traces to a primary, official source. This page documents where the data comes from, how it is verified, and how often.

Sources

The regulatory facts rendered across the hub and the guides come from:

• Federal Register — executive orders and their implementation notices (e.g. EO 14324, which ended the $800 de-minimis exemption on 29 August 2025).
• U.S. Customs and Border Protection — enforcement announcements and entry-process guidance.
• USITC Harmonized Tariff Schedule — the live HTSUS, the authoritative source for base duty rates and tariff-line classification.
• Supreme Court of the United States — slip opinions, e.g. Learning Resources, Inc. v. Trump (No. 24-1287, 20 February 2026), which struck down the 2025 IEEPA tariffs.
• Congress.gov / CRS — Congressional Research Service legal sidebars summarizing the rulings and the replacement measures.
• USTR — Section 301 list assignments for China-origin goods.

How verification works

• Every regulatory claim on this site carries a verification date. The current dataset was verified on 12 June 2026 against the sources above.
• The dated facts live in one machine-checked dataset inside the site's codebase; automated tests lock each value to its citation, so a value cannot silently drift from the source it claims.
• Each guide shows two dates: "Last updated" (when the page content last changed) and "Data verified ... against ..." (when the facts were last re-checked, with the sources linked).

Refresh cadence

• The regulatory dataset is re-verified on a monthly refresh cycle, and immediately after major events (a court ruling, a new executive order, a tariff expiry).
• If more than 30 days pass since the verification date, the site marks its data as stale rather than pretending freshness.
• The next scheduled watch item: the Section 122 surcharge's 150-day window ends 24 July 2026.

The regime as verified on 12 June 2026

• De-minimis ($800 exemption): eliminated 29 August 2025 (China-origin earlier, 2 May 2025) — still suspended.
• IEEPA 2025 tariffs: struck down 20 February 2026; CBP ceased collection 24 February 2026.
• Section 122 surcharge: 10% ad valorem, all origins, 24 February – 24 July 2026, HTSUS 9903.03.01.
• Section 301 (China): in force, 7.5–25% by list. Section 232: in force, product-specific.

What the calculators promise — and what they don't

The family's calculators produce planning estimates: they apply the published rates to the values you enter. They do not produce binding classifications or rulings — CBP makes the final determination on every entry, and declared values, classification calls, and courier fees can move the real bill. For commercial imports above $2,500 or restricted-category goods, consult a licensed customs broker.