At the 2015 edition of the conference Belgium: The State of the Federation, we started to explore the tricky question of how to measure (sub)national identities in surveys and wondered whether different measurements lead to different results. Five years later, we go back to this question with some more data from Belgium, not only from voter surveys but also from MPs surveys. Indeed, in Belgium, as in many so-called multinational countries, there is a tradition of measuring national and subnational identities, but it is an uneasy business as it relies on several assumptions on what’s behind identities. In surveys, most often three types of questions have been used: the hierarchical question (asking respondents to which of a list of given identities they feel most closely related in the first and in the second place), the Linz-Moreno question (asking respondents to situate their regional and national identity in light of each other), the metric question (asking respondents to situate themselves on distinct identity scale). In this paper we compare these three different types of measurements and wonder whether they do measure the same phenomenon or not. Such endeavour should allow us to refine our measurements and open new ways to measure (sub)national identities.