Harmonized Tariff Schedule of the United States · HTS code · HS 8421.21
8421.21.00: For filtering or purifying water
Water filtering and purifying machinery
Not declarable on its own: use one of its 1 subdivisions Data: Harmonized Tariff Schedule of the United States · checked on 24 October 2026
- 8421 Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases; parts thereof:
- Filtering or purifying machinery and apparatus for liquids:
- 8421.21.00 For filtering or purifying water
What you pay
Importing into USA
US additional duties of HTS chapter 99 in force on 22 October 2026 are included (Section 301, 232, 338 and 201). IEEPA duties are no longer collected after the Supreme Court ruling of February 2026. Conditional exemptions (US content, end use, metal share) are not computed: check the provision.
Additional duties and import rules
Charges on top of the customs duty, and rules the goods must meet at the border.
No additional measures recorded for this origin.
Same subheading in other tariffs
8421.21 For filtering or purifying water
UK Free Third-country duty 2 tariff lines 
EU 1.7% Third-country duty 1 tariff line 
Türkiye 1.7% Third-country duty 1 tariff line 
Canada Free Third-country duty 1 tariff line 
Mexico Free – 5% Third-country duty 5 tariff lines · average 2% 
Brazil 20% Third-country duty 1 tariff line 
Argentina 12.6% Third-country duty 2 tariff lines 
Peru Free Third-country duty 2 tariff lines 
New Zealand Free Third-country duty 1 tariff line 
Japan Free Third-country duty 1 tariff line 
Taiwan 3.4% – 4% Third-country duty 2 tariff lines · average 3.7% 
GCC 5% Third-country duty 4 tariff lines 
Switzerland Free Third-country duty 1 tariff line 
Norway Free Third-country duty 1 tariff line 
North Macedonia Free Third-country duty 1 tariff line 
Nigeria 5% Third-country duty 2 tariff lines Binding rulings for similar goods
Decisions of U.S. Customs and Border Protection (CROSS) and HMRC (Advance Tariff Rulings) on goods classified here. A ruling binds only its holder, but shows how the authorities classify similar goods. The descriptions are the authorities’ own, in English.
- N361715 U.S. CBP
The tariff classification of a robot pool cleaner from Vietnam
- N360559 U.S. CBP
The tariff classification and country of origin of the Lex Aqua closed-loop water treatment system
- N359248 U.S. CBP
The tariff classification of a robotic pool skimmer from China
- N359001 U.S. CBP
The tariff classification, country of origin, and eligibility of the United States-Mexico-Canada Agreement of an Electrochemical Water Purification System
- H345780 U.S. CBP
Application for Further Review of Protest No. 2704-23-168738; Classification of Sand and Cartridge Filter Systems from China
- N357946 U.S. CBP
The tariff classification and country of origin of a water filtration device
- N354669 U.S. CBP
The tariff classification of an aquarium gravel cleaner from China
- N353710 U.S. CBP
The tariff classification of water filter components from the United Kingdom
Legal notes
HTS code 8421.21.00 is a line of the Harmonized Tariff Schedule of the United States under HS subheading 8421.21 (for filtering or purifying water).
The general duty is free, and quantities are declared in p/st.
For the same subheading, the UK duty is free, the EU duty is 1.7%, the Türkiye duty is 1.7%, the Canada duty is free, the Mexico duty is 0%–5%, the Brazil duty is 20%, the Argentina duty is 12.6%, the Peru duty is free, the New Zealand duty is free, the Japan duty is free, the Taiwan duty is 3.4%–4%, the GCC duty is 5%, the Switzerland duty is free, the Norway duty is free, the North Macedonia duty is free and the Nigeria duty is 5%.
The United States imported goods of subheading 8421.21 worth US$2bn in 2024; the largest supplier was Canada.
Questions and answers
What is the USA import duty for HTS code 8421.21.00?
The general duty in the Harmonized Tariff Schedule of the United States is free; the supplementary unit is p/st. Preferential rates for goods from agreement countries, anti-dumping duties and VAT are not included.
Where does the United States import these goods from?
For subheading 8421.21 as a whole, the largest supplier in 2024 was Canada (US$449m), followed by China.
Typical products
- electro magnetic water purifiers
- filter presses, for liquids
- hot tub water purifier
- water filters
- water purifying machinery and apparatus
- water purifying systems
Everyday names, not part of the legal text.