This article looks at UK-based think-tanks and their communicative and cooperative networks with other actors in Britain and beyond. Which institutions and people do British think-tanks talk to most to exert influence on domestic public policy? What forms do such communications take? What are British think-tanks' objectives for cooperation with non-UK organisations? This article is based on a survey with analysts at British think-tanks that was conducted in 2012. The data suggests that while British think-tanks communicate and co-operate intensively with some actors within Britain, contacts and cooperation with organisations outside the UK are rather lacklustre. Particular actors are more important for advocacy think-tanks than they are for academic think-tanks; some actors have very little importance for either type.