Plausibly, only moral agents can bear action-demanding duties. This places constraints on which groups can bear action-demanding duties: only groups with sufficient structure—call them ‘collectives’—have the necessary agency. Moreover, if duties imply ability then moral agents (of both the individual and collectives varieties) can bear duties only over actions they are able to perform. It is thus doubtful that individual agents can bear duties to perform actions that only a collective could perform. This appears to leave us at a loss when assigning duties in circumstances where only a collective could perform some morally desirable action and no collective exists. But, I argue, we are not at a loss. This article outlines a new way of assigning duties over collective acts when there is no collective. Specifically, we should assign collectivisation duties to individuals. These are individual duties to take steps towards forming a collective, which then incurs a duty over the action. I give criteria for when individuals have collectivisation duties and discuss the demands these duties place on their bearers.