Parliamentary administrators have to cope with a complex and ever-changing procedural framework, as well as with conflicting demands from the policy side. Nevertheless, their role in inter-parliamentary cooperation is rather under-researched. This article focuses on the actors of Administrative Parliamentary Networks and introduces two entirely new entities: European Programmes; and networks of Parliamentary Budget Offices, which seem to have escaped scholar’s attention. Administrative duties and roles are discussed in the context of inter-parliamentary cooperation and a new role is attributed to parliamentary administrators, that of the researcher. Existing findings from previous studies are put under a new light and analysed with the support of empirical data.