We operate from Belgium. We only have to charge the Belgian tax rate (21%) for other Belgian companies or consumers living in the EU, in all other cases VAT rat

We operate from Belgium. We only have to charge the Belgian tax rate (21%) for other Belgian companies or consumers living in the EU, in all other cases VAT rate is 0% (have to put a disclosure on the invoice referencing Belgian law though). Then again we don't sell any physical goods (luckily). We don't automatically check validity of VAT number, so maybe I'll be able to answer that question in a couple of months.