In recent years, test-based accountability (TBA) has emerged as a powerful device to steer public services at a distance. Within the current governance scenario, TBA allows the State to retain regulatory powers over the broader range of education actors that operate in increasingly complex and multi-layered education systems. This chapter analyses why and how TBA has been rapidly disseminated and adopted as a key mechanism of regulatory governance in education worldwide. The chapter shows that the global diffusion of TBA responds to a combination of drivers of a different nature, namely discursive, political, technologic, and economic. The chapter also shows that, despite the current consensus around the desirability of TBA’s adoption, the most relevant international organisations in the education policy field are disseminating this policy technology with different goals and through different rationalities and instruments. (In: A. Wilkins and A. Olmedo (eds). Education governance and social theory: Interdisciplinary approaches to research. London: Bloomsbury).