With the new EC rules that have come into force this month and the new requirement to submit EC sales lists for reverse charge services, some of you will be having to obtain your customers' VAT registration numbers for the first time. You do need to be certain that these are accurate numbers and there is a facility known as "VIES" on the EC commission website where you can enter a VAT registration number from any EC country and it will confirm whether or not the number itself is a valid number. Here's the link: http://ec.europa.eu/taxation_customs/vies/vieshome.do?selectedLanguage=EN.
Marie