The universal basic income (UBI) has found its way into public debates and has prominent advocates across almost all political camps. In many debates, it is presented as a solution for the consequences of a large variety of current societal challenges, such as unemployment, over-education, ecological crises, gender inequality and issues related to digitalization and automatization. While UBI has been discussed broadly from an expert position, we know very little about the population’s perceptions of UBI. Thus, to shed light on the public legitimacy of UBI as a radically different concept of social justice and citizenship, our contribution uses data from large group discussions where participants explicitly refer to the UBI as an option for a future welfare state. By comparing debates in Slovenia and Germany, we unearth that the perspective adopted by the participants towards a UBI is strongly shaped by the welfare institutions of the countries in which they live and the social justice principles embodied in those institutions.