Regarding the +21% on invoice payments, you’ll have to mark the checkbox that the invoice is inclusive VAT.
Another way is to book it as usual and make a journal entry like:
Te vorderen BTW / Voorheffing
Aan Af te dragen BTW EU / Verwerving binnen de EU
(English readers please excuse for using the Dutch phrases as I don’t know the English ones)
BUT, there’s good news: I got word that they’re going to work on EU VAT! 