Why HTS Codes Are Critical to Understanding Your Vulnerability to Tariffs

Article Highlights:

• The Harmonized System, or HS, is a product classification system developed and maintained by the World Customs Organization (WCO) that allows countries to refer to a universal standard when identifying and classifying products and determining trade duties.
• The HTS, or Harmonized Tariff Schedule, is the United States’ trade system for classifying products and assessing duties for all goods imported into the country. 
• Contrary to popular misconceptions, the HTS database covers not just products but parts, minerals, chemicals, and raw materials. It’s designed, in other words, to capture all imports, regardless of where they sit on the continuum between raw materials and finished products. 

The installment of a new presidential administration in the U.S. has come with a dramatic shift in America’s trade policy. Although President Trump’s predecessor, Joe Biden, adopted an aggressive approach toward China’s massive export industry, his administration generally did not interfere with the status quo in the U.S.’s trade relations with the rest of the world. That status quo has been all but abandoned in 2025, however. The Trump administration has embraced a protectionist strategy that seeks to extract significant concessions from myriad countries in exchange for their access to America’s import market—which, at $3.8 trillion, is easily the most valuable in the world. 

As of the third week of February, President Trump has introduced a 10% across-the-board tariff on Chinese goods; established 25% tariffs on steel and aluminum imports; announced plans to institute an additional 25% tariff on semiconductors, pharmaceuticals, and auto parts; and set forth a plan to impose “reciprocal tariffs” that will match the duties other countries attach to goods imported from the U.S. This maelstrom of executive measures is shaking up the trade landscape for thousands of American businesses, forcing importers to scrutinize their supply chains to understand what goods, subassemblies, and parts are or will soon be subject to this flurry of new tariffs. 

In order to identify which of their goods fall under new or existing import rates, companies need to familiarize themselves with two crucial trade “languages”: the Harmonized System (HS) and the Harmonized Tariff Schedule (HTS).

In order to identify which of their goods fall under new or existing import rates, companies need to familiarize themselves with two crucial trade “languages”: the Harmonized System (HS) and the Harmonized Tariff Schedule (HTS).

What Is the Harmonized System (HS)?

The Harmonized System, or HS, is a product classification system developed and maintained by the World Customs Organization (WCO) that allows countries to refer to a universal standard when identifying and classifying products and determining trade duties. According to the WCO, the HS has over 5,000 commodity groups, which are each assigned a six digit code. Over 200 countries currently use the Harmonized System, and 98% of all international trade is classified in the HS. 

What Is the Harmonized Tariff Schedule (HTS)?

Drawing from the international HS, the Harmonized Tariff Schedule is the United States’ trade system for classifying products and assessing duties for all goods imported into the country. While the HTS uses the same six-digit code as the Harmonized System, the U.S. system assigns products an additional four digits—two for the specific duty rate of the product being imported, and another two that function as a statistical suffix.

The U.S. International Trade Commission (ITC) publishes and maintains the HTS, while Customs and Border Protection enforces the schedule and its accompanying tariff rates at all 328 official U.S. ports of entry. 

What Is an HTS Code?

An HTS code is the ten-digit code assigned to goods by the International Trade Commission. According to the U.S. Census Bureau, there are currently around 19,000 distinct HTS codes. The first two digits of an HTS code are known as the “chapter,” which refers to one of 99 different chapters in the HS and HTS classification systems. The next two digits refer to the “heading,” which is an additional layer of classification that further narrows the category of commodities. The next two digits comprise the “subheading” or the specific product itself. Taken together, these first six digits constitute the universally recognized Harmonized System code.

The final four digits are what distinguish the U.S.’s HTS classifications from the worldwide HS code. The first two of these numbers create what is known as the “rate line,” which CBP officials use to determine the duty rates on imported goods. The final two digits are referred to as the “statistical suffix”; they create a ten-digit “fingerprint” of an item for trade research and data collection purposes. 

Why HTS Codes Are Essential to Understanding Your Tariff Obligations

All tariffs for goods imported into the U.S. are administered through the HTS. CBP officials and classification experts use this system—along with the accompanying U.S. International Trade Commission-Tariff Database—to categorize products and assign corresponding duty rates. 

In order to understand their tariff obligations, importers should familiarize themselves with these same resources. They can utilize the U.S. International Trade Commission (USITC) Tariff Database, and then execute an HTS search for their imported item, to get a sense of what their duty obligations are. Having direct access to a product or part’s HTS code—whether through a supplier, a commodity’s documentation, or other related materials—is always preferable, however, as it gives businesses a more accurate look at any potential tariffs they may incur when importing the goods. 

The Difference Between Schedule B and HTS Codes

Schedule B functions for U.S. exports in the same way that the Harmonized Tariff Schedule operates for imports. While the HTS is maintained by the U.S. International Trade Commission, Schedule B is published by the United States Census Bureau. As with HTS codes, the first six digits of all Schedule B codes follow the Harmonized System (HS) code for that product. 

To determine the Schedule B code for a specific product or commodity, exporters can use the Census Bureau’s search engine available on the Schedule B site. 

How to Look Up HTS Codes for Products and Parts

Importers can access the USITC database, and then conduct an HTS search, to identify the 10-digit codes for imports. It’s important to remember, however, that identifying a code on this database that you believe matches your import does not guarantee that it will be classified in the exact same way by the federal government. “The duty rate you request is only as good as the information you provide,” Customs and Border Protection explains on its website. “The actual duty rate of the item you import may not be what you think it should be as a result of your research.”

Do All Imports Have HTS Codes?

Contrary to some popular misconceptions, the HTS database covers not just products but parts, minerals, chemicals, and raw materials. Chapter 28 of Section VI, for example, covers “Inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or of isotopes.” This chapter encompasses HTS codes for the chemical elements, inorganic acids, and sulfur compounds, among other substance categories. Other chapters of the Harmonized Tariff Schedule cover classifications ranging from silk and cotton to iron, steel, and aluminum. 

The HTS, in other words, is designed to capture all imports, regardless of where they sit on the continuum between raw materials and finished products. 

Understanding HTS Classifications and Duty Rate Columns

While importers can certainly use the USITC’s HTS database to search for their product, they may also want to familiarize themselves with the full landscape of the schedule itself in order to get a better sense of how their products are likely to be classified by CBP officials when entering the U.S. 

If you were importing raw sandstone, for example, you would scroll down to Chapter 25, titled “Salt; sulfur; earths and stone; plastering materials, lime and cement.” Within this chapter, “crude or roughly trimmed” sandstone has three columns corresponding to three different duty rates. The “General” column, which reflects the duty rate for all countries with normal trade relations (NTR) with the U.S., has no duties. Businesses importing sandstone from countries with NTR with the U.S., therefore, do not need to pay any tariffs. The next column, which normally displays rates for countries with special trade agreements with the U.S., is empty (if the “General” column is free, then the “Special” column will be free, too). 

Finally, Column 2 is reserved for countries the U.S. does not have normal trade relations with. As a result, this column typically has higher duty rates. Current Column 2 countries include Cuba, North Korea, Russia, and Belarus. Manufacturers importing sandstone into the U.S. from any of those four countries will have to pay a duty rate of $5.30/cubic meter.

Navigating the Harmonized Tariff Schedule Is Arguably More Important Than Ever

We’re still in the earliest stages of the Trump administration, and there have already been enough new tariffs introduced and enacted to dramatically alter the global trade landscape. U.S. companies that draw from international supply chains have to not only adapt to this onslaught of new trade barriers; they need to start developing a strategy that gives them the agility and litheness to respond to those restrictions that are still to come. In order to be able to do this effectively, organizations need to conceptualize trade compliance as more than just a series of finite, limited actions. They need to embrace a more dynamic approach, one that maintains resilience and flexibility in the face of a trade environment arguably more volatile than it’s been in generations.

 We’re still in the earliest stages of the Trump administration, and there have already been enough new tariffs introduced and enacted to dramatically alter the global trade landscape.

In addition to developing proficiency with HTS codes and the Harmonized Tariff Schedule, companies can also make use of a powerful supply chain risk management (SCRM) solution like Z2Data. The Z2Data platform has multiple tools that allow businesses to manage all their trade compliance responsibilities, including comprehensive supplier profiles with compliance information, detailed intelligence on risky sub-tier entities, and a sanctions forecasting feature that shows users a list of global firms most likely to become targeted by sanctions in the near future. And for organizations looking to diversify their supply chains to shift away from impending tariffs, Z2Data offers supplier databases, supply chain mapping, and a suite of other in-depth resources.

To learn more about the Z2Data platform and how its tools can help you effectively mitigate the costs of new tariffs, schedule a free demo with one of our product experts.