If you are using BigCommerce v3, it allows you to add customs information such as Country of Origin and HS Tariff Codes when editing or creating products in the control panel, as well as by API.
If your store is using BigCommerce v2 (legacy version), this information can only be added by using their API. You will need to contact your developer if you do not know how this is done.
For more information, visit the dedicated BigCommerce help article for your store version:
Adding Products (v2) experience
If you are using BigCommerce v2, and prefer to add your customs information directly in ReadyToShip, visit out dedicated help article here.
Once you have added customs information to your products in your BigCommerce store, these details will automatically be imported into ReadyToShip with any new orders placed in your store AFTER you have added all the codes.
For existing orders in ReadyToship before you added the codes in Shopify, you will need to add them directly in ReadyToShip by following these steps.
When adding HS Tariff Codes, please do not add any decimals, just leave those out and add the whole number.