Please note that based on case law and the EU VAT Directive for conferences the local VAT regulations of the location of the event are applicable (21%) for all purchases. EU VAT Directive:

Supply of services

On 1 January 2010, rules were introduced to ensure that VAT on services will better accrue to the country of consumption [see Directive 2008/8/EC adopted by the EU Council of Ministers and the press release IP/08/208.