In the emerging field of biometric identity registration, much is known about the potential of established e-ID programs for improving living conditions of people in the developing world, but also about these projects’ contingencies, inefficiencies and unintended consequences. Yet, despite its arguably critical impact on the lenses of state vision, the interaction of policy makers with donor agencies and the private sector in the planning, design, and implementation of e-ID projects remains a troubling blind spot. To address this knowledge gap, my project explored how categories of measuring and authenticating identity come into being at the intersection of global development agendas, international “card cartels” (Lyon 2003), the political economy of “biometric capital” (Breckenridge 2014), and local political practices and perceptions in Ghana’s ongoing biometric identity registration project. Officially launched on 15 September 2017, the new Ghanacard provided an ideal case for this endeavor due to its complex layering of settings (across local, national and international scales) through which biometric devices, measurement practices and models for application (as well as the perceptions, desires, and capacities they engender), circulate in the production of the Ghana’s new biometric population register.