Like many countries in the Global South, Sierra Leone has recently embarked on the biometric identification of its citizens and residents in the aim to achieve ‘legal identity for all’ (Sustainable Development Goal 16.9). Given their limited access to documentation, many people rely on self-reporting or recommendations in the registration process. Based on ethnographic research, this article examines the work of Justices of the Peace to deliver affidavits (documented oaths) as a central avenue for the biometric enrollment of undocumented, often-marginalized citizens in Sierra Leone’s civil register. Their case suggests that intermediaries between the digitizing state and citizens indeed work as ‘brokers of citizenship’, because beyond only certifying citizenship, their intermediation brings citizenship in four different meanings into being. They provide crucial orientation on the meaning of citizenship, fix citizens’ identities, perform their own understandings of citizenship with potentially exclusionary effects and distribute responsibility for citizenship claims along a wider citizenship infrastructure.