The outsourcing of education services has been widely adopted across international contexts as a 'tested solution' or panacea to meet various educational problems including school management, curriculum design, teaching and student discipline. Contracting third-party providers, it is argued, enhances organisational goals such as efficiency, quality and school improvement. However, the outsourcing of education services has also impacted on established notions concerning the boundaries around teachers' work. This paper deploys the framework of discursive institutionalism to offer insight into how the idea of outsourcing has been activated and circulated by discursive communities in three diverse international settings. Despite its problem-solution logic, the institutionalisation of outsourcing creates its own problems, not least the undermining of teacher professionalism, the 'businessification' of schools and a diminishing of their educational mission.