This paper derives from a program of research which aims to develop a robust framework for cross-national comparisons of internal migration. Stage one examined the obstacles to such comparisons and made proposals for a battery of 15 migration indicators covering four broad dimensions of population mobility which were then tested using British and Australian data. Wider implementation requires assembly of databases for countries around the world. Stage two takes the first steps towards this goal by establishing a worldwide inventory of contemporary practice with respect to collection of internal migration data, based on published sources and a comprehensive survey of national statistical agencies. Information collected includes the source and type of data, migration intervals and zonal system. This paper summarises the conclusions from Stage 1, reports results from the Stage 2 inventory and sets out proposals for a collaborative network to implement the cross-national indicators worldwide