Evidence-based policies to monitor and manage migration flows require accurate data. Data collection on international migration flow statistics is based on a range of data sources and measures. Discrepancies in reported migration flow data are apparent when comparing flow statistics from receiving countries on the number of arriving migrants by their country of origin with statistics from sending countries on the number of departing migrants by their country of destination. In recent decades the relative incompleteness and non-comparability in reported migration statistics have motivated a number of initiatives to improve data in European countries. In this paper we illustrate graphically the discrepancies between sending and receiving migration flow statistics provided to Eurostat by European countries. We find a reduction of the discrepancies between receiving and sending migration flow data after the implementation of regulations to improve the availability and comparability of migration data.