Do I have to pay VAT even if my organisation has a European VAT number?
Yes, as there is a difference on VAT of goods or services. VAT on the events like on services is paid at the place where the service has been supplied (Hungary). This will most often, but not always, be where the service supplier is established (Hungary). The trader will in those cases account for VAT on his services in the Member State where he is established, applying the VAT rate of that country (25%). Fore more detailed information, please visit: http://ec.europa.eu/taxation_customs/taxation/vat/how_vat_works/index_en.htm There might be some exceptions. Some international organisations such as UN have an official statement that they are exempt to pay VAT. In this case we require receiving a copy of the document.
