VTUPB2200 - Trade unions and professional bodies: Criteria that all the bodies must fulfil: "Referable only to its aims"
Supplies do not benefit from the “group 9” exemption unless they relate to the aims of the organisation as set out in its articles of association, constitution or rules. For example, if the organisation were a trade union, the exemption would cover supplies made in connection with negotiating pay or other working conditions, such as meetings held for formulating pay demands. Exemption would not cover supplies that are unconnected with such employment-related activities: for example, purely social functions like an annual dinner dance would be excluded.