This article studies the categorization of social space in five European countries (Germany, Belgium, Spain, France and Poland). It relies on the analysis of the reception of a prototype conceived by social science researchers for Eurostat: the European Socioeconomic Classification (ESeC). Beyond the comprehension of the logics governing this prototype, our work points out how “ordinary” people understand the structuration of social space in different national contexts. And indeed, by studying how interviewees react when they are confronted with ESeC categories, we are able to simultaneously address how they develop their own categories to orient themselves in social space. Through an experimental research based on a list of professions, classified according to the ESeC categories, we test the self-consistency of the prototype when it is submitted to uninitiated people. Our results demonstrate that the main organization principles of ESeC are not easy to understand for our interviewees. We conclude by questioning the capacity of such a European nomenclature to take into account the various national socioeconomic realities that still characterize the European Union.