If someone is a paid-up member of a political party or other organization, they have paid the money needed to become an official member. a fully paid-up member of the Labour Party
If a person or country is a paid-up member of a group, they are an enthusiastic member or are recognized by most people as being a member of it. our future as an independent nation lies as a fully paid-up member of Europe
A policy on which all premium payments have been made Although you have not died, you need not make any more payments, and your beneficiary is assured a full death benefit
If you pay up, you give someone the money that you owe them or that they are entitled to, even though you would prefer not to give it. We claimed a refund from the association, but they would not pay up