"Why doesn’t Commerce/Magento/$otherSolution handle my taxes properly? That’s the most basic feature!” - many people, often.
When it comes to eCommerce, nobody likes taxes. We expect taxes to “just work”, so we can finish our projects and get on with our lives. At the same time, no other topic is as complex.
Selling online puts us at the crossroads of different (and sometimes conflicting) laws with many rules and even more exceptions. All eCommerce systems provide the basic tools (“Define your tax rates and specify when to apply them”) and make the site developer responsible for tax compliance. The developer usually passes that responsibility to the client, sometimes implicitly. The client consults an accountant, sometimes. But the buck has to stop somewhere, and it often comes back to the developer, 5 days after launch.
As taxes become more and more complex, there is a need for smarter tax handling, where the application does more and the site administrator less. In the Commerce 1.x lifecycle we’ve built the commerce_vat module to handle the more and more complex VAT taxes. For 2.x, we’re bringing this approach back into core, and releasing several libraries to share the solution with the wider PHP community.