Slibstream supports HS Codes (Harmonized Standard Codes) for calculating customs duties for products.
Slibstream does not automatically search or define HS codes for your WooCommerce products. HS codes need to be sourced and entered manually.
Below are 3 useful tools designed to help you find HS Codes for your products.
Free HS Code Search Tools
United Kingdom Trade Tariff: Look up commodity codes, duty and VAT rates
https://www.trade-tariff.service.gov.uk/sections
United States of America: International Trade Commission
https://hts.usitc.gov/
Parcel Force Worldwide: Tariff Code Search
https://apps.parcelforce.com/tariffcode