Do you pay sales tax on a camper if live in Illinois and buy it Iowa?

Yes, you will have to pay sales tax on the camper in Illinois.

According to the Illinois Department of Revenue, you must pay sales tax on any purchase of a vehicle, including campers, if you are a resident of Illinois and the vehicle is delivered to you in Illinois.

Since you live in Illinois and took delivery of the camper, you will have to fill out an Application for Certificate of Title and registration (Form VSD 190), pay sales tax, title, and registration fees and purchase two years' worth of Illinois license plate stickers.