Originally posted by dlh I'm guessing that most "ebay" sellers that charge sales tax on out-of-state transactions are not actually registered, and are not forwarding the "tax" collected to the appropriate states.
eBay acts as the agent in the transaction and is responsible for collecting the tax here in Washington. It is added during checkout and the seller is none-the-wiser. Jurisdiction in this case is aided by the fact that eBay has physical presence here in the form of server-farm infrastructure, though Washington does not actually consider such at present.
As for the tax itself, it is a "use" tax assessed on the sale amount. If I buy something in Oregon (a mere seven miles away) and bring it home with me, theory is that I owe tax, but only if the state can prove I have used the item in Washington. If I mail the item, unused, to someone outside Washington, no tax should be owed, at least in theory. I am unaware of anyone attempting a refund for in-state purchases mailed as gifts.
Steve