If you sell digital products (SaaS, ebooks, etc.) by USA based company to EU clients, you have to apply VAT of EU country where the client is based (Belgium 21%, Hungary 27%, Ireland 23%, etc).
I don't, I actually have everything with Beanstalk (private repos)
inb4 someone says "that's $$$ that you could be spending on yo momma" -- I used to sleep with one of their execs and put me the plan they give their employees.