U.S. tariffs for importing kits and sets of products and multifunctional machines to America

On this page, we discuss the American customs standards that guide the classification and assignment of tariffs for three specific categories of products: Kits, Sets, and multifunctional products.

• A kit is a set of unassembled parts and pieces that, once assembled, become a finished product.
• The essential character guides the customs classification and thus the calculation of U.S. tariffs for sets of products.
• The main function is the basis of American customs classification for multifunctional machines and products.

U.S. tariffs for importing kits to America: unassembled products to be assembled

A kit is a set of unassembled items that, once assembled, form a finished good. The classic example is unassembled Ikea furniture: a box containing separate pieces that, once put together, become a table.

According to American customs regulations, an item imported into America unassembled but presented as a set of components intended for assembly must be classified as the finished product, despite its unassembled form. In other words, this unassembled table is a table — and therefore constitutes a kit. 
 

U.S. tariffs for importing a set of products to America

The mere presence of multiple items in the same packaging is not enough to configure a set of products for tariff calculation purposes. What constitutes a “set” according to American customs regulations? To be qualified as a set under U.S. customs standards, the items must:

1. Consist of at least two different products, classifiable under separate headings;
2. Be packaged together for retail sale;
3. Be intended to satisfy a specific need or perform a particular activity, in combination.

Typical examples of products constituting a set:

• a fondue set (pot, burner, skewers, fuel),
• a rifle sold with a case and a box of cartridges,
• a toolkit

These cases satisfy the “common activity” rule.

Example of what is not a set: A coffee mug packaged with a pen:

• Meets requirements 1 and 2,
• but not requirement 3: the two items do not contribute to a common activity.

Therefore, even if they are sold together in the same packaging, they must be classified separately, with separate classification and customs code, separate valuations, distinct origins, and, potentially, different import duties.
 

Customs classification for sets of products

The essential character guides the customs classification and thus the calculation of U.S. tariffs for sets of products.

Once the condition to qualify a product as a set is met, the critical concept of essential character comes into play, as stipulated by American customs regulations. The U.S. Customs and Border Protection (CBP) analyzes the set to determine Which element gives the set its economic-functional identity, which guides its customs classification.

Example: the rifle with case and cartridges

• 1 rifle + 1 case + 1 box of cartridges:
  The essential character is provided by the rifle → the entire set is classified as a rifle.

Reverse scenario

• 500 boxes of cartridges and a “gift” rifle:
  In this case, the cartridges prevail → changes the essential character → changes the classification.

For American customs purposes, the essential character of a set of products is not predefined and can be determined based on:

• value,
• volume,
• weight,
• cost,
• prevalent function,
• role of the components,
• also qualitative elements (design, presentation, color, marketing)

Extreme example:
500 boxes of cartridges + an engraved Perazzi rifle worth $200,000.
Here, the rifle — not the cartridges — clearly dominates the essential character.
The economic-functional concept of the set is reversed.

CBP extensively uses this criterion because it determines the applicable customs heading, the U.S. tariff, and the correct declarative compliance for importing into America.
 

Importing multifunctional machines and products into America

The main function is the basis of American customs classification for multifunctional machines and products.

The concept of main function typically applies to multifunctional machines or composite systems, like in the case of a home security system composed of cameras, sensors, hub, and monitor. The logic differs from the essential character:

• Essential Character → evaluates the components of a set.
• Main Function → evaluates the prevalent intended use of a multifunctional product or machine.

If the system's purpose is surveillance, then the prevalent element is represented by the cameras, even if the other components are relevant.

The main function is based on:

• intended use;
• design of the device;
• user perception;
• marketing and prevalent economic function.

Example of customs classification for America of a multifunctional product

In 2025, clock radios still exist. But what are they, from a customs perspective?

• “An alarm clock with a radio?”
• “A radio with an alarm clock?”

The answer does not depend on the consumer's personal use but on the analysis according to American customs regulations of the main function :

• If the prevailing purpose is to display time → classification as a clock.
• If the prevailing purpose is to listen to the radio → classification as a radio.
• If the design and marketing present them as radio devices with a secondary alarm function, this directs the customs classification analysis.
• Conversely, if they are sold for the alarm function, the radio may be considered secondary.

The decision is never automatic: it requires qualitative analysis, review of technical characteristics, examination of marketing documentation, and interpretation of American customs standards.