I'm looking to implement automated tax calculations for an ecommerce solution. I am looking for something that would provide either some form of online gateway/web services for querying, or a delimited database of sorts for download. It would need to include U.S. tax rates by county (i.e. tied to ZIP code), as well as specify whether tax is to be charged on shipping/handling/similar fees.
Does anyone have some recommendations for something out there, or advice for where to start?
