International HS

The WCO revises the Harmonized System approximately every five years, adding headings for new products and restructuring obsolete categories — requiring importers to verify that classifications remain valid after each new edition takes effect.

The HTSUS conforms to the international HS at the 6-digit level but diverges through U.S.-specific 8-digit subheadings, additional U.S. notes, and independent national classification decisions — meaning a foreign country's classification of identical goods is not controlling for U.S. purposes.

WCO Classification Opinions are formal decisions of the Harmonized System Committee on how specific goods should be classified in the HS — persuasive authority in U.S. practice, with weight depending on U.S. voting position and the opinion's direct applicability.

The WCO Explanatory Notes are the official commentary on the Harmonized System — persuasive but not legally binding in U.S. classification, they are the most authoritative external guide to HS heading scope and intent.