The United Nations Disaster Assessment and Coordination, (UNDAC) handbook is intended as an easily accessible reference guide for members of an UNDAC team before and during a mission to a disaster or emergency. The handbook is not an authoritative instruction but rather represents an accumulation of institutional memory related to processes and procedures for coordination as seen in the scope of the UNDAC terms of reference. Its focus is on the how to of coordination but also includes sufficient context to ground the user in the Office for Coordination of Humanitarian Affairs' (OCHA) mandate. It gives guidance on coordination functions and structures as well as helping trouble shoot coordination barriers that may be encountered. It provides an insight into coordination resources, partners, and important contextual information that may contribute to UNDAC effectiveness.