This is how it was supposed to be in WI, but they never went after the people that didn’t. All purchases are supposed to be taxed, if you aren’t charged them online, then you were required to do it when you file taxes. Interestingly enough, I believe there was a bill recently passed requiring all online stores to charge sales taxes for all states by a certain time. Might be why some do and some don’t have it in their systems yet.