Care, state, and kinship are deeply entangled. Ideas about kinship translate into rights and obligations to care, and forms of belonging, including citizenship. Notwithstanding the social scientific critique, naturalising belonging through kinship remains prominent in public discourses. Technologies underlying paternity and genomic testing build on shared ideas about the importance of descent as constituting kinship, which then translate into various forms of political belonging. This generates inclusion (for some) but also difference and the exclusion of ‘other’ internal and external populations. Given recent discourses on immigration, also in connection with securitisation, the topicality and urgency of kinship measuring in relation to state and care remains undiminished. This research project seeks to explore how kinship measurements are used as state practices to attest care obligations and thereby simultaneously to political belonging.