This chapter explores the balance in curricular policy between input regulation (for example prescription of content) and output regulation (for example accountability mechanisms). The chapter draws upon two case studies, England and Scotland, which have adopted diverging approaches to curriculum regulation, identifying the current balance in each country between input and output regulation. Drawing upon an ecological understanding of teacher agency, we conclude the chapter with an analysis of the extent to which England and Scotland are centralised or decentralised systems, and the relative freedom of teachers in each case to engage in school-based curriculum development