As international migration grows, it is becoming increasingly important for the public and policymakers to understand migratory flows and the impact of migration on individuals, families, societies and economies. A longitudinal approach is particularly useful for such understanding, collecting information from the same individuals or households over time to reveal the geographic and socio-economic outcomes of the migration experience. To that end, this publication provides an overview of longitudinal data sources for migration statistics and their dissemination, alongside guidance on how to develop the relevant data set for these statistics using integrated data. Though this approach is complex and challenging, the Guidance also illustrates how apparent limitations can be addressed