it's 5% the declared value of the package. just need to make sure the correct code is entered in the shipping invoice. typically you'll get billed for it later, but there are some couriers that require you to pay the duty first before they deliver it to you. also, some states track import shipments and will require you do pay "use tax", which is equivalent to your sales tax, when you file your state taxes. if you don't list it in your state filed taxes, you'll get a penalty added to what you owe. this happened to me on a couple Wals I had imported in ☹️