Vienna Convention Bureau - VCB
International congresses with a minimum of 50% of the participants from a foreign country

Union of International Associations - UIA
International congresses organized or supported by international organizations (associations, societies, federations) with at least ten participants, which are either already listed in the international UIA Yearbook or eligible for inclusion

International Congress & Convention Association - ICCA
International congresses organised on a regular basis with a minimum of 50 participants that move between at least 3 different countries
 

Number of events 2018-2023

Vienna's international ranking 2023