Homelessness prevention has become the dominant policy paradigm for homelessness services across the developed world. However, services have emerged in a piecemeal and selective manner, often restricted to particular towns and cities, with no requirement on local authorities to intervene. Wales is the first country where the government has sought to fully reorient services towards prevention and to make services universally available. At the heart of the Welsh approach is a pioneering legal duty on local authorities to help prevent and relieve homelessness. This paper draws upon administrative data and interviews with both service providers and service users to examine the first year of implementation under the new system.