All signs point to the eventual closing of long-standing loopholes that let you buy stuff online without paying sales tax. The key question is who will have to collect the tax when someone buys something from a third-party seller on Amazon: Amazon or the merchant?
https://www.seattletimes.com/business/amazons-sales-tax-fight-is-heating-up-as-states-crack-down/A 25-year-old U.S. Supreme Court case established the rules many online merchants follow today. The ruling barred North Dakota from forcing Quill, a mail-order office-supply operator, to levy sales tax because the company lacked a physical presence in the state.
For many years, Amazon hewed to the Quill ruling and didn’t collect sales tax — even on the stuff it sold itself. But the company gradually changed its position as it built warehouses all over the country, giving it a greater physical presence in multiple states. Amazon now collects sales tax on inventory it owns directly in all states that levy such taxes.
But about half of its sales are goods owned by 2 million merchants posting products on its site. Amazon leaves tax collection up to them, and many maintain that’s not their responsibility. That’s why shoppers pay tax on some Amazon purchases and not on others.