[jakejohnson]

Yes, there are affordable sales tax APIs available for calculating sales tax. Usually massive lookup tables are at the zip / postal code level and don't provide enough granular detail by jurisdiction to accurately collect sales tax. They also don't contain logic around product exemptions, customer exemptions, shipping taxability, sales tax holidays, etc. I recommend using an API if you want to avoid under-collecting or over-collecting sales tax.

However, this is a HUGE change. Instead of registering for a sales tax permit and remitting tax for one state, smaller merchants will have to do this in many states if they meet a certain threshold. They will likely have to use sales tax compliance software to aggregate all of their transaction data across multiple platforms (Amazon, eBay, Walmart, etc) and their shopping cart, then report / remit accordingly.