Thanks, @DavidP!
I have such a module, I use the tb/PS native one. But how do I set up a trade account? I have a customer group "Wholesale", but I don't see where I can exclude taxes for intra-EU sales. That's where the module comes in, I guess.
This is the only module I found: https://addons.prestashop.com/de/b2b/18149-umsatzsteuerbefreiung-auf-rechnungen-fur-b2b.html
It doesn't look complete, though. Prices should be net only where we have an intra-EU sale, not within the same country. The module doesn't solve that.
How did you solve this?