Official References

Sources

Source categories used to structure TariffCatalog formulas, trust notes, and verification reminders.

Last reviewed: July 2026Estimate-only customs toolsVerify before filing

CBP

US customs guidance and e-commerce import rules.

USTR

Section 301 and US tariff action references.

USITC HTS

US Harmonized Tariff Schedule lookup.

UK Trade Tariff

UK commodity codes and import duty references.

EU TARIC

EU integrated tariff reference.

Shopify HS codes

Shopify product customs information guidance.

Source Policy

Official sources first

TariffCatalog prioritizes official customs, tariff, tax, postal, and platform documentation. Secondary sources can help explain workflows, but duty rates and filing-sensitive claims should be verified against official databases before filing.