Harmonized Tariff Schedule (HTS)
https://hts.usitc.gov/current
Schedule B Search Engine (Shipper Export)
https://uscensus.prod.3ceonline.com/
CBP Ruling Online Search System
https://rulings.cbp.gov/home
CBP Informed Compliance Publications
https://www.cbp.gov/trade/rulings/informed-compliance-publications
U.S. –Mexico- Canada Agreement (USMCA)
https://www.cbp.gov/trade/priority-issues/trade-agreements/free-trade-agreements/USMCA
Section 301 (China Tariffs) Search Tool
https://ustr.gov/issue-areas/enforcement/section-301-investigations/search