ˌpaid-ˈup BrE AmE adjective British English informal
1 . a fully paid-up member of something if someone is a fully paid-up member of a particular group, they strongly support what that group likes or believes in:
a fully paid-up member of the celebrity circuit
2 . paid-up member someone who has paid the money needed to be a member of a club, political party etc:
The competition is open to all paid-up members of the Women’s Institute.