# United States tariff lines under HS 8421.21

> The United States tariff splits HS 8421.21 (filtering or purifying machinery and apparatus for liquids: For filtering or purifying water) into 1 national line: 8421.21.00.00 (for filtering or purifying water). Every United States line under 8421.21 is free of general (MFN) duty.

Source: https://border.bot/countries/united-states/hs-codes/842121
Last updated: 9 October 2026

[Countries](https://border.bot/countries) / [United States](https://border.bot/countries/united-states) / [Chapter 84](https://border.bot/countries/united-states/hs-codes/84) / [8421.21](https://border.bot/countries/united-states/hs-codes/842121)

## Key facts

- HS subheading: [8421.21](https://border.bot/hs-codes/842121)
- Duty (MFN): Free
- National lines: 1
- Tariff: [United States](https://border.bot/countries/united-states)
- Chapter: 84: Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof

## United States lines under 8421.21

The United States tariff splits HS 8421.21 (filtering or purifying machinery and apparatus for liquids: For filtering or purifying water) into 1 national line: 8421.21.00.00 (for filtering or purifying water).

Every United States line under 8421.21 is free of general (MFN) duty.

- [8421.21.00.00](https://border.bot/countries/united-states/hs-codes/8421210000) Filtering or purifying machinery and apparatus for liquids, For filtering or purifying water. Duty (MFN): free

## In other countries

No other national tariff on border.bot has live lines under 8421.21 yet.

- [The Harmonized System text for 8421.21](https://border.bot/hs-codes/842121)

- Previous subheading: [8421.19](https://border.bot/countries/united-states/hs-codes/842119) Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases; parts thereof
- Next subheading: [8421.22](https://border.bot/countries/united-states/hs-codes/842122) Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases; parts thereof

## Frequently asked questions

### How many national tariff lines does the United States tariff have under HS 8421.21?

The United States tariff splits HS 8421.21 (filtering or purifying machinery and apparatus for liquids: For filtering or purifying water) into 1 national line: 8421.21.00.00 (for filtering or purifying water).

### What is the duty on HS 8421.21 in the United States?

Every United States line under 8421.21 is free of general (MFN) duty.

## Sources and updates

The tariff lines for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The duty rates for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The trade programmes for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

This page was last updated on 9 October 2026.

Guidance from published tariff data, not a binding ruling. For a decision customs must follow, apply to the destination’s customs authority for a binding tariff ruling.

Official source files:

- https://hts.usitc.gov/reststop/exportList?from=0000000000&to=9999999999&format=CSV&styles=false

Machine-readable: https://border.bot/countries/united-states/hs-codes/842121.json