This briefing paper is part of an ongoing research initiative on humanitarian coordination. It outlines key issues and questions related to decision-making, one of the four themes that will be discussed at ALNAP’s meeting ‘Working Together to Improve Humanitarian Coordination’ in London on 30 June to 1 July 2016. In particular, it will concentrate on decision-making within the Inter-Agency Standing Committee (IASC) coordination mechanism (Clusters, inter-Cluster and humanitarian country teams, or HCTs). Alongside this paper, ALNAP has also produced additional materials for background context including a video on the same topic, which can be accessed at www.alnap.org/coord-meeting.