This paper addresses the methodological challenges of analyzing university students with migrant backgrounds, using data from the University of Milano-Bicocca. As migrant populations grow, particularly second and middle generations, understanding their diverse subgroups—such as second-generation students—has become increasingly important. However, inconsistent data recording in university datasets complicates this analysis. We propose a methodology that combines administrative records with an original targeted survey to fully identify and differentiate these subpopulations. The main contribution is the creation of an enriched administrative dataset, which provides a robust foundation for analyzing the characteristics of students with migration histories across all routinely collected variables.