Methodologies for gathering and analysing remittances data differ across countries and organisations. Many countries derive their remittances data using the Balance of Payments manual developed by the IMF. Some use version 5, and some use version 6, and still others use a mix of both or something else entirely. This information is often based on the reporting requirements the respective central banks have set for commercial banks and and other operators in their market. The World Bank uses this data, when available, as well as other calculations, including migrant stock estimates to calculate the inflows, outflows and corridor level remittances flows. These calculations are based on the World Bank’s own methodology. KNOMAD, who prepare the World Bank remittance flows data answers more questions regarding these differences here.