> That only makes sense for an online store that's going to ship you something, in which case asking for the destination ZIP code up front solves that problem

> That only makes sense for an online store that's going to ship you something, in which case asking for the destination ZIP code up front solves that problem Tax boundaries do not follow zip code boundaries. To actually find the right tax rate you need the full address, including suite or apartment number because there are cases where a tax boundary runs between different suites at the same street address. Also this is not just for online stores that ship something. It also applies if you are selling a downloadable good like a game or music, or selling memberships to your site.