Partnership working between institutions and organisations is currently commonly seen as providing solutions to meeting multiple, interrelated needs in areas of social policy including health, social welfare and education. This article examines and discusses the policy and practice of such collaboration in an educational context. Drawing on studies of state-funded interventions into 14-19 provision in England it offers insights into why and how schools, colleges and other organisations involved in education and training collaborate. It concludes that partnership is highly locally contingent. National policy on partnership working, which is itself not consistent, is strongly mediated by local contextual factors, institutional values and interests, personal missions and careers, pragmatic opportunism, ad-hocery and happenstance. The interplay of these factors is highly dynamic and changes over time. (Contains 2 figures.)