HS Code for Water Filtration Systems
The HS Code for water filtration systems is 842121. The MFN duty rate for importing to the US is 2.4%.
| HS Code (6-digit) | 842121 |
|---|---|
| US Duty Rate (MFN) | 2.4% |
| EU Duty Rate (MFN) | 1.7% |
| Chapter | 84 |
| Heading | 8421 |
| Last Updated | 2026-05 |
Description
Machinery for filtering or purifying water
HS Code 842121 covers machinery for filtering or purifying water with a US MFN duty rate of 2.4%.
Frequently Asked Questions
Does the filter media material affect the classification of a water filtration system under HTS 842121?
Yes, the filter media material is a critical factor. Systems using semi-permeable membranes for reverse osmosis or nanofiltration are specifically classified under 842121. However, systems designed solely for ion-exchange using resin beds may be classified elsewhere, such as in heading 8421 or 3914, depending on their primary function.
What are the common customs inspection risks for water filtration systems classified under HTS 8421.21?
The primary risk is detention for incorrect classification if the system incorporates UV lamps or chemical dosing components, as these may shift classification to heading 8543 or 8424. Inspectors may also verify that the system's declared value includes all filters, membranes, and control panels, which are considered part of the functional unit.
What additional import costs, beyond the duty rate, should I expect when importing water filtration systems under HTS 8421.21?
For water filtration systems, you will typically incur a 2.4% Most Favored Nation (MFN) duty rate. Additional mandatory costs include a 0.3464% Merchandise Processing Fee (MPF) and, if applicable, a 0.125% Harbor Maintenance Fee (HMF) on vessel shipments. These fees are calculated on the entered value of the goods.
Material Classification for Water Filter Cartridges
The material of the filter element is critical for classifying replacement cartridges under HTS 842121. For example, ceramic or diatomaceous earth filter elements generally remain under this provision. However, cartridges primarily using activated carbon (often from coconut shell or coal) are classified elsewhere, typically under HTS 3812.10 (activated carbon). Similarly, cartridges where the filtration function is secondary to another process, like ion-exchange resin cartridges for water softeners, are classified under HTS 3914.00. Always verify the primary constituent material to ensure correct classification of consumable filter parts.
Distinguishing Similar Filtration & Purification Systems
Water filtration systems under 8421.21 are often confused with other purification equipment. Key alternatives include 8421.99.90 for parts of water filtration systems, which is a common error. For ultraviolet (UV) or ozone-based water purifiers, consider heading 8543 (electrical machinery). Additionally, simple filter cartridges made of ceramic or activated carbon may fall under 8421.99 or even 6815.99 (ceramic articles) or 3914.00 (ion exchangers) if they lack a housing and pump. Always verify the primary function and the presence of a pressure mechanism to ensure correct classification.
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