We continue the work initiated in [1–3], where the acceptance logic, a modal logic for modelling individual and collective acceptances was introduced. This logic is aimed at capturing the concept of acceptance qua member of an institution as the kind of attitude that agents are committed to when they are “functioning as members of an institution”. Acceptance logic can also be used to model judgement aggregation: it deals with how a collective acceptance of the members of an institution about a certain fact ϕ is created from the individual acceptances of the members of the institution. The contribution of this paper is to present a tableau method for the logic of acceptance. The method automatically decides whether a formula of the logic of acceptance is satisfiable thereby providing an automated reasoning procedure for judgement aggregation in the logic of acceptance. Key words: Semantic tableaux method, acceptance logic, judgement aggregation, discursive dilemma