Quoted from flashinstinct:
So If I get this right.
Let's say I live in an area close to Minneapolis that only charges the baseline tax and someone from Minneapolis buys something from my online store. I would have to charge the baseline tax + the Minneapolis tax?
And sadly, no, it's not based on zip code. You can have different sales taxes in the same zip code. This is why it will be a nightmare for small businesses. Why do you think Amazon was in favor of it now? They're established, and this will help prevent smaller companies from rising up to compete with them. If you want to support local business, you should be against this.
And then some states charge different taxes based on what you buy - or charge nothing at all. In Minnesota, there's no taxes on clothing, for example. So a lot of people will drive here from Wisconsin (border state) to buy clothing, even though the rest of their sales tax is lower in Wisconsin.
To get the list of all of the different sales taxes, you have to buy software and it costs quite a bit. At one of my first jobs, we received the sales tax updates on tape once a month, and I had to load it into our finance database monthly because they change more frequently than you'd think since there's thousands of different areas that have different rates.