This special issue investigates citizenship and belonging in mixed-status families, i.e. families consisting of both citizens and non-citizens. We critique the standard perception of citizenship as ‘hard on the outside and soft on the inside’. For citizens with non-citizen family members, the exclusionary nature of citizenship is very much ‘inside’, in the very heart of their families. We deploy the concept of ‘performing intimate citizenship’ to understand how citizens deal with migration regulations that hinder them from living with their families. Often this is a first, shocking confrontation with state intervention into their private lives. Protesting such interventions–in court, in collective mobilisation, in letters to the authorities–involves making claims both about who belongs and about what ‘proper’ family is. Thus, citizens and their non-citizen family members ‘perform intimate citizenship’: they express what citizenship is and should be, by mobilising intersecting conceptions of intimacy and of belonging.