While I am not yet a full-timer I have done craft shows all over the East coast. If you are talking about sales taxes, they will have to be paid to the state where you are selling. If you are talking about income taxes, they will be paid to federal and your state of residence. When you register for a show that is not in your home state they will usually help you get a temporary license or at least tell you how to go about getting it. Whatever you do, make sure you keep the books correctly and pay your sales taxes as you are much more likely to be audited over sales taxes than income taxes. I currently own a small business in NM and do some craft shows here but will probably stop when we go full-time. If you are selling on line you have a whole different set of rules.