The Harmonized Tariff Schedule (HTS) is the key to many things related to importing goods. It affects duty rates, anti-dumping orders, tariff reductions or additional duties, and government agency requirements among other things.
Your supplier may have provided you with an HTS Code, but the importer is the one who’s liable if it turns out to be the wrong one. If you don’t know, or are unsure of, the HTS Code for your goods, you can try Flexport's HS Code Lookup Tool. There is also a searchable function on the USITC site.
Correctly identifying your product’s HTS Code on your own can be tricky, but your Flexport customs broker can help to correctly classify your product and estimate the customs duties you will need to pay upon importing to the U.S.