"If you order online, and the company you order from does business in your state — that is, the company is headquartered in your state, or has retail stores in your state — then you have to pay state sales tax. If the company does not do business in your state, you don't have to pay the tax for online orders.
I would then guess that if you have a company registered in another state, it works the same way except as if you were living in that other state.
Someone correct me if I'm mistaken!"
Kid of sort of. The business has to be headquarter in the state I believe. Things are kind of foggy now that my state (California) has been screwing around with sales tax. When I order from Amazon, there's no tax as it's headquartered in Seattle Washington. When I order from Newegg, there is Ca. sales tax as it's headquarters are only about 100 miles from me.