Since 2015, Niger has been actively committed to migration control in West Africa in the context of the European Union Emergency Trust Fund for Africa. To enable better comprehension of the making of security in Niger, this article studies the implementation of biometrics under the EU Trust Fund by international agencies (Interpol, the International Organization for Migration, UNHCR) and national actors. Drawing on in-depth interviews, observation and anthropology of aid studies, I argue that biometrics is a travelling organizational model translated into a multiscalar process by state and non-state actors embedded in relations of power. Biometric technologies cannot be reduced to an added-value instrument for Nigerien authorities in order to enhance legibility, to better identify Nigeriens and foreigners crossing Niger’s borders within the free-movement area of ECOWAS (Economic Community of West African States). I focus on heterogeneous actors’ situated discourses and practices to demonstrate that they do not share the same dream about biometrics. In practice, however, biometrics helps international actors to produce their own security knowledge in Niger that, in the end, augments the capacity to trace ECOWAS citizens and reinforce the EU border regime.