The outcome and democratic legitimacy of Union Citizenship has been extensively debated in the existing academic literature. Yet, the debates take place in various (sub-)fields and are only loosely connected, if connected at all. Further, the arguments in the existing literature are often based on standards of democracy that are not appropriate to the European Union’s (EU) current construction. Drawing on the theoretical approach of multilateral democracy, I develop normative standards for political membership and political rights specifically for multilevel systems. At the empirical level, I examine the effect of supranational institutional structures on citizens’ perceptions in the domestic political systems; and the effect of domestic institutional structures on citizens’ perceptions of having voices in the multilevel system as well as their evaluation of EU democracy. The theoretical and empirical research findings relate to the policy debate on how to (re)design citizenship in the EU. I focus on the EU as the most developed form of democratic governance structures beyond the nation-state, but the normative arguments are transferable to other multinational polities.