General Rules of Interpretation (GRI)
The General Rules of Interpretation (GRI) are the six legally binding rules that govern every HTSUS classification determination. Published at the front of the HTSUS and carrying the force of law, they must be applied in strict numerical sequence: GRI 1 is always evaluated first, and a later rule may only be invoked when the prior rule is genuinely insufficient to resolve the classification.
In Detail
The GRI were developed by the World Customs Organization as part of the international Harmonized System Convention and appear in substantively identical form in every WCO member country's national tariff schedule. In the United States, they are incorporated directly into the HTSUS and have been repeatedly upheld as binding law by the U.S. Court of International Trade and the Court of Appeals for the Federal Circuit.
The six rules address progressively more complex classification situations. GRI 1 resolves the vast majority of classifications through the heading text and applicable notes. GRI 2 extends heading coverage to incomplete goods and mixtures. GRI 3 resolves goods that are prima facie classifiable under two or more headings through three sequential sub-tests. GRI 4 is a residual rule for goods not resolved by 1–3. GRI 5 addresses cases, containers, and packing. GRI 6 applies GRI 1–5 by analogy to determine subheading-level classification.
The sequential constraint is legally significant: a later GRI rule may only be applied after confirming that all prior applicable rules genuinely fail to resolve the classification. A classifier cannot invoke GRI 3 because a product is complex — they must first establish that GRI 1 and GRI 2 are insufficient. This sequencing requirement is enforced in CBP rulings, protest proceedings, and CIT decisions.
Classification Significance
The GRI are not interpretive guidelines or best practices — they are law. A classification determination that cannot identify the specific GRI rule applied, explain why prior rules were insufficient, and cite the heading text or notes that support the classification is not legally defensible against CBP audit or protest. Correct GRI application is the technical core of every auditable classification.
How Kanon Handles This
Kanon's classification engine applies the GRI in strict legal sequence for every product. It evaluates GRI 1 first, documents whether it resolves the classification, and advances to the next rule only when the prior rule is genuinely insufficient. The specific rule applied — and the basis for each prior rule being inapplicable — is documented in the Classification Support Package.