Fair tax?

We should talk more about remittances sent from the U.S. to other countries, like when Pierre sends money back to his family in Quebec. When I buy stuff in a neighboring state, I am obliged to pay a tax to the state in which I live, to offset the loss of sales tax revenue. Maybe something like that is in order for remittances. Should people be able to shield their income from state sales tax by sending it across the border?