When You Need to Understand the “Why” Behind a Tariff Heading

Explanatory Notes: The Classification Resource You’re Probably Not Using

There’s a reason some tariff classifications seem to defy logic. You’re staring at the HTS description, the Chapter Notes look right, and yet something doesn’t add up. The duty rate is higher than you expected, or worse, you’re facing a challenge from CBP.

That missing piece is often the Explanatory Notes.

If you’ve never heard of them, you’re not alone. Most importers (and a few brokers) go their entire careers without cracking them open. But Customs authorities do. In fact, the Explanatory Notes are one of CBP’s go-to references when tariff classifications get messy.

And if they’re using them, you should be too.

What Are Explanatory Notes?

The Explanatory Notes are essentially the “legislative history” of the Harmonized System (HS). They are written and maintained by the World Customs Organization (WCO) and serve as the official interpretation of the HS headings and subheadings.

Think of them as the director’s commentary for the HS. They:

• Explain the intended scope of headings and subheadings
• Provide examples of products that are included—and those that aren’t
• Clarify ambiguous language in the heading and subheading descriptors
• Offer context for terms that don’t exactly roll off the tongue, like “coherent optical arrangements” or “saddlery and harnesses”

But here’s the catch: they aren’t legally binding in the U.S.

CBP isn’t required to follow them, but it usually does. Explanatory Notes are frequently cited in CBP rulings and in trade court decisions. If you’re building a defensible classification strategy, you can bet CBP is going to flip through those Notes before they hand you a decision.

How Explanatory Notes Support (or Destroy) Your Classification

If you’ve ever been certain you had the right HTS code, only to be told you’re dead wrong, it’s probably because of an Explanatory Note you didn’t know existed.

We once had a client importing optical fiber cables that seemed to fit cleanly under 7019. It wasn’t until we reviewed the Explanatory Notes that we saw a clarification: the specific fibers they were importing were carved out explicitly in 8544, where the duty rate was significantly lower.

A simple oversight? Sure. But it cost them six months of retroactive duties and a reclassification that could’ve been prevented with a five-minute review of the Notes.

Why They’re Overlooked (and Why You Shouldn’t Overlook Them)

The main reason Explanatory Notes are ignored is simple: they’re hard to get. Unlike the HTSUS, which is freely available online, the Explanatory Notes are locked behind a paywall. You either have to purchase them directly from the WCO or subscribe to a trade service that provides access.

But price isn’t the real barrier. The real issue is that few people know how valuable they are until they’re sitting across from CBP, trying to explain why their interpretation of a heading doesn’t match the one outlined in the Notes.

And here’s a bit of irony for you: CBP has a subscription. They read the Notes. They make decisions based on them. If you’re not, you’re playing the game with half the rulebook.

The Competitive Advantage of Actually Reading The Explanatory Notes

Most importers don’t read Explanatory Notes because most importers don’t even know they exist. But those who do? They have a significant edge.

When you understand the logic behind each heading, you can build a tariff strategy that is grounded in certainty.

Imagine going into a tariff dispute knowing exactly why CBP is classifying your product the way they are and being able to counter it with specific, written guidance from the very document they’re using.

That’s not just playing defense. That’s knowing the playbook.

Get It Right the First Time

Most classification errors aren’t due to bad intentions. They’re due to incomplete information. If your tariff strategy relies on descriptions alone – or worse, Google searches – then you’re putting yourself at risk.

Explanatory Notes are the missing layer. They provide the context and clarity that HTS codes and Chapter Notes can’t. And if you don’t read them, CBP will happily read them for you, while you pay the difference.

Need a Second Opinion?

O’Meara & Associates can help you navigate the fine print and build a classification strategy that holds up to scrutiny. We dig into the Notes – General, Section, Chapter, and Explanatory – so you don’t have to guess.

Reach out today. Let’s make sure your strategy is built on solid ground, not shaky assumptions.