France has one of the most unequal levels of access to childcare in Europe, despite high public investment. Existing literature explains this inequality through factors such as the availability of childcare slots, social stratification, stigmatisation, attitudes, cultural biases, and parental logistical constraints. However, the role of administrative barriers in exacerbating access problems remains understudied. We provide fresh insight by examining these barriers in France’s poorest county. Seine-Saint-Denis offers a revealing case study, as its inadequate childcare coverage persists despite heavy public investment – highlighting challenges within France’s multi-layered administrative system. Drawing on interviews with families and childcare managers, as well as participant observation in the local early childcare system, we identify administrative barriers at three levels: ‘organisational’, ‘procedural’, and ‘individual’. Our findings suggest that difficulties in accessing childcare stem from: (1) the failed logic of integration between different administrative layers and the financing modality of the Single Service Provision (PSU), (2) the opaque criteria employed by childcare admission committees (CAMAs), and (3) the lack of adaptation of the multi-layer administrative system to family needs. The article investigates administrative barriers to welfare state access, approaching for the first time the domain of childcare.