This paper attempts to provide a remedy to a surprising lacuna in the current discussion in the epistemology of expertise, namely the lack of a theory accounting for the epistemic authority of collective agents. After introducing a service conception of epistemic authority based on Alvin Goldman’s account of a cognitive expert, I argue that this service conception is well suited to account for the epistemic authority of collective bodies on a non-summativist perspective, and I show in detail how the defining (...) requirements of an expert can apply to epistemic groups. (shrink)