The population census is one of the most important sources of official statistics, informing decisions about almost every aspect of life within the UK and its communities. These include: policy decisions informed for example by understanding the pressures on transport networks and housing stock; guiding support to particular communities by evaluating the extent and nature of disadvantage in the UK, and investment decisions, such as where to place new schools or supermarkets. It is of fundamental importance in allocating billions of pounds to local areas by the UK government and devolved administrations, as well as grants to voluntary sector organisations. And the census helps every person in the UK get a better understanding of the places in which they live and work. This report brings to a close the Assessment of the official statistics from the three censuses conducted in 2011 in England and Wales, in Scotland, and in Northern Ireland.