Securing and maintaining humanitarian access is critical to the work of the Norwegian Refugee Council (NRC). Increasingly, humanitarian agencies responding in complex, conflict-affected contexts recognise the benefits of coordination to promote access. NRC commissioned this review to make informed decisions on whether and how to engage in different joint access mechanisms, what mechanisms to advocate for, and who would be best placed within a country team to represent NRC in different fora. To understand how humanitarian access coordination mechanisms are functioning in practice, initiatives in Afghanistan, the Central African Republic (CAR), Somalia and South Sudan were studied in depth.