# Importing into the US: HTS, extra layers on Chinese goods, ISF

US duty starts from the 10-digit HTS code. Goods of Chinese origin can carry several additional duty layers on top, which changed often recently. Ocean imports also need an ISF filing before loading.


## How the duty is calculated

1. Customs value: generally the transaction value, without international freight.
2. General duty rate for the 10-digit HTS code.
3. Additional layers for Chinese origin. These are published separately from the base schedule and have changed several times; always check the current state.
4. Processing and harbor maintenance fees.

## Before loading

The Importer Security Filing (ISF) is due before the goods are loaded on the vessel. Late filing can be penalised.



## Sources

- [USITC Harmonized Tariff Schedule](https://hts.usitc.gov/)

Canonical: https://purserhouse.com/en/guides/us/