The United Nations Statistics Division (UNSD) is responsible at the international level for collecting and disseminating official national data on international migration.

The United Nations Statistics Division collects statistics on international migration flows and on the stock of migrant population through the Demographic Yearbook data collection system. The collection of international migration data is shared among different institutions in order to minimise the burden on countries.

The International Labour Organisation (ILO) collects and compiles international labour migration statistics.

The United Nations High Commissioner for Refugees (UNHCR) collects and compiles data on asylum seekers and refugees more specifically on asylum applications, refugee status determination, recognition rates, refugee populations and movements, demographic characteristics (age and sex) as well as major refugee locations (camps, centers, urban areas, etc.).

The United Nations Population Division prepares estimates of migrant stock for each country using the data provided by the United Nations Statistics Division; undertakes regular studies on national policies on international migration and assesses the impact of international migration on development.