Each state has a different amount (6.5% where I live), no federal tax so while states can charge anywhere from no to 10 or11%, still less than 20%. And everyone kinda knows what their state tax is, you would either pay yours or the state you buy it from and the store figures out what to send to the state dept of revenue. It's just what you get used to. The only difference is that in recent years the taxing states have tightened up the revenue laws to make sure they collect the tax no matter where you are buying. All by computer!