HTS Code Classification Guide: How to Find the Right Tariff Code

What Is an HTS Code?

An HTS code (Harmonized Tariff Schedule code) is a 10-digit number that identifies every imported product entering the United States. It determines your duty rate, Section 301 tariff exposure, and eligibility for trade agreement benefits. Getting it wrong — even accidentally — can cost you tens of thousands of dollars in excess duties or trigger a CBP penalty for intentional misclassification.

The HTS is maintained by the U.S. International Trade Commission (USITC) and is updated periodically. The first six digits are internationally standardized under the World Customs Organization's Harmonized System (HS). The final four digits are US-specific statistical suffixes that determine the precise duty rate.

Anatomy of a 10-Digit HTS Code

Take the code 3926.90.9990 as an example — a common catch-all for plastic articles:

The duty rate is determined at the 8- or 10-digit level. Two products that share the same 6-digit HS heading can have meaningfully different US duty rates depending on their statistical suffix.

The General Rules of Interpretation (GRIs)

The GRIs are the six rules that govern how every HTS classification decision must be made. CBP auditors apply these rules, and your customs broker should be too. Understanding them helps you evaluate whether a reclassification argument is defensible.

GRI 1 — Classification by heading text and section/chapter notes

Most products are classified under GRI 1. You identify the heading that most specifically describes the product, considering any legal notes in the section or chapter. Chapter notes can exclude products from a heading even when the heading text seems to fit.

GRI 2 — Incomplete or unfinished articles; mixtures

GRI 2(a) extends headings to cover incomplete or unfinished articles that have the essential character of the complete article. GRI 2(b) covers mixtures or combinations of materials.

GRI 3 — Goods classifiable under two or more headings

When two headings could apply, GRI 3 provides a hierarchy: (a) the most specific heading wins; (b) if equally specific, classify by the material or component that gives the product its essential character; (c) if still tied, use the heading that appears last in the tariff schedule.

GRIs 4–6

GRI 4 is a catch-all (classify with most similar goods). GRI 5 covers packing materials and containers. GRI 6 applies the same logic at the subheading level.

Common HTS Classification Mistakes

These are the errors CBP sees most frequently in audits — and the ones that trigger the largest duty recovery demands:

• Using a generic "other" subheading when a specific one exists. If your product has a dedicated heading, classifying it as "other articles of plastics" (3926.90.9990) likely understates the duty rate and is defensible only if no specific code applies.
• Classifying by primary material rather than function. A plastic serving spoon is not an article of plastics — it's a kitchen utensil. Functional classification often produces lower duty rates and is frequently more correct under GRI 1.
• Ignoring set and composite goods rules. Products sold together as a set are classified based on the component that gives the set its essential character under GRI 3(b).
• Using the wrong country of origin. Section 301 and IEEPA tariffs depend entirely on the country of origin, not the country of export. Goods assembled in Vietnam from Chinese components may still be Chinese-origin for tariff purposes.
• Not checking for Chapter 99 exclusions. Some products on Section 301 lists received temporary exclusions under specific Chapter 99 provisions. These exclusions may still apply or may have expired.

How to Verify an HTS Code via USITC

The authoritative source for HTS code verification is the USITC's online tariff database at hts.usitc.gov. To verify a code:

• Search for the 10-digit code or its 6-digit heading
• Confirm the code appears in the current schedule (codes change periodically)
• Read the Column 1 General rate — this is the MFN duty rate
• Look for Chapter 99 footnote references in the rate column — these indicate Section 301 or other special tariffs
• Check any applicable section or chapter notes that might modify classification

Alternatively, use our free HTS lookup tool, which queries the USITC API directly and surfaces Section 301 status, the base duty rate, and total effective rate in one place.

How CBP Enforces Classifications

CBP uses several mechanisms to audit and enforce classifications: post-entry audits (CF 28 requests for information), focused assessments targeting specific importers, and Compliance Measurement surveys across product categories. When CBP determines a misclassification, it can assess:

• Back duties — unpaid duties for up to four years prior
• Interest — on unpaid duties from the entry date
• Penalties — ranging from two to four times the unpaid duty for negligence; up to the full domestic value for fraud

When to Get a Binding Ruling

A CBP binding ruling (also called an advance ruling) gives you a written determination from CBP on how a specific product should be classified. It's legally binding on CBP for that product, providing the best possible protection against a future audit finding.

Binding rulings are published in the CBP CROSS database and are searchable by HTS code or product description. Before pursuing a reclassification, check CROSS for existing rulings on similar products — they indicate which direction CBP tends to classify products like yours and how defensible each alternative is.

Our HTS audit tool searches CROSS automatically and includes relevant ruling citations with each alternative classification suggestion.