I would never recommend Avalara to anyone who uses Magento. They are unfamiliar with their own platform, let alone Magento. They have no idea how their own API works. I got conflicting tech support every single time I called. I was given the number of the firm that originally built their product, Classy Llama, and when I called them, they were so fed up with Avalara and told me terrible things about working for them. They offered to fix my problem with the integration for $5000. In months of working with Avalara they were never able to sync any part of their API. Not only did the most basic part of their extension not work, their address validation component broke our cart. Eventually they told me they would not support my installation, when they realized that they had no idea how to. They offered me a refund and now its been 3 months trying to get them to refund my installation while they continue to charge me for future services. I can't get my rep to respond for almost 2 months. I finally got them to remove the current charge, but they refuse to reply to me about the original charge.