Burdensome is an understatement. Between cities, counties and states levying sales tax, there are thousands of taxing entities. In some cases, it's impossible

Burdensome is an understatement. Between cities, counties and states levying sales tax, there are thousands of taxing entities. In some cases, it's impossible to determine the proper tax rate without a nine-digit zip since city boundaries may split zip codes, meaning city+county or just county might apply in different parts of a zip code area. Forcing the customer to enter a nine-digit zip and then possibly choose between multiple tax options when it's still not clear leads to an incredibly high friction checkout. The main winners in this fight are the companies that provide sales tax computation components or APIs for web services. However, I think having a sales tax based on location of seller rather than buyer doesn't make as much sense. The big companies like Amazon would find loopholes that allowed them to originate from low/no tax areas and smaller sites without the ability to relocate would be stuck with most of the burden. This just changes the fight from big box vs. internet to small site vs. big site.