Why HTS Classification Requires More Than Just a Code Search

The Notes Nobody Reads (But Everyone Should)

If you’re relying on a keyword search or a code look-up tool to classify your imports, you’re playing a risky game. HTS classification isn’t just about matching a description, it’s about following a legal framework built on layers of fine print that most people never bother to read.

Unfortunately, “most people” includes a lot of importers, customs brokers, and even compliance professionals. And it shows.

When classification errors happen – and they happen a lot – they usually trace back to one simple problem: someone skipped the notes.

The Four Types of Notes You Should Actually Be Reading

The Harmonized Tariff Schedule of the United States (HTSUS) is more than just a list of codes. It’s a legal document, structured with rules, exceptions, and conditions that govern how each code should be used. To properly classify anything, you need to understand and apply the four major types of notes:

1. General Notes

Found at the very beginning of the HTSUS, these cover:

• Free Trade Agreements (FTA)
• Special duty programs (like the Generalized System of Preferences)
• Industry-specific programs (automotive, pharmaceuticals, civilian aircraft)
• Definitions critical to interpreting the rest of the schedule

General Notes explain who qualifies for reduced or duty-free treatment and who doesn’t. They’re updated regularly (often more than once a year), and skipping them can mean missing out on significant savings or accidentally making unsupported claims.

The General Notes are US-specific.

2. Section Notes

Published by the World Customs Organization, the Harmonized System is the basis for all Harmonized Tariff Schedules, including the HTSUS.  Each of the 21 sections of the HS may have its own Notes, or set of rules, that apply to all the chapters inside it.

The US added Section XXII that includes chapters 98 and 99.

 Section Notes often define:

• What is (and isn’t) included in a section
• How certain materials or technologies are treated
• Cross-references to other sections

If you classify based on headings alone without checking the Section Notes, you’re operating half-blind. CBP won’t see it that way.

3. Chapter Notes

Every chapter (there are 98 in the HTSUS) has its own notes.  The Chapter Notes are written by the WCO and address classification at the heading and subheading level.  However, some chapters include “Additional U.S. Notes” that are US-specific.  

These get even more specific, often spelling out:

• Definitions of key terms
• Exclusions that aren’t obvious from the headings
• How to treat mixed materials or unfinished goods

Many misclassifications happen because someone thought they understood a heading but ignored a Chapter Note that completely changed the interpretation.

For example, many consider Viton(r) to be a synthetic rubber.  To classify articles of Viton(r) in chapter 40 (Articles of Rubber) would be incorrect because it is, in fact, a plastic. We addressed this here.

4. Explanatory Notes

Written by the World Customs Organization (WCO) and addressing classification to the six-digit level, Explanatory Notes provide deeper guidance on how headings are interpreted globally.
They:

• Offer real-world examples
• Clarify ambiguous or complex headings
• Serve as a reference used heavily by customs authorities (including CBP)

While they aren’t binding U.S. law and are not dispositive, they are persuasive and often cited in Customs rulings and court cases. If you want to understand how CBP is likely to view your classification, the Explanatory Notes are where you look.

Additionally, it will be difficult to convince Customs you are practicing reasonable care if you do not routinely consult the ENs in your tariff classification justifications.

Why Skipping the Notes Is a Costly Shortcut

Most misclassification cases we see didn’t happen because someone tried to cheat the system. They happened because someone relied on a heading title or a quick keyword match without reading the legal structure that governs it.

Examples we encounter regularly:

• Classifying a product under a broad heading without realizing the Chapter Notes exclude it.
• Claiming an FTA preference without checking the General Notes for eligibility conditions.
• Missing a special duty program that could have saved thousands—because the General Notes were never reviewed.

Classification isn’t about intuition or “what sounds right.” It’s about following the legal trail starting with the notes.

Get It Right From the Start

If it’s been a while since anyone read the General, Section, or Chapter Notes tied to your classifications, or if the Explanatory Notes sound more like a rumor than a resource, it’s time to take another look. 

Tariff classification isn’t guesswork. It’s a legal process built on rules most people skip. Those who don’t skip them usually pay a lot less in duties (and penalties). In a tariff environment that’s growing more volatile by the month, understanding the fine print gives you a serious competitive advantage.

In classification, what you don’t read will cost you.

Need a second opinion on your classifications?

O’Meara & Associates helps importers cut through the complexity and build defensible, strategic tariff classifications. If you’re ready for a closer look or just tired of hoping your current codes will hold up, get in touch with us today.