In the EU, VAT exempt customers are companies (business-to-business, B2B commerce) with EU VAT numers in the EU country of destination. It is necessary to prove that the product has been transporterd to the other EU Member State.
The invoice must be issued for the EU tax number issued in the respective Member State Country. However, if the buyer does not have an EU Tax Number in another Member Stae Coutry, Hungarian VAT must be applied.