This paper explores the complex landscape of alternative provision across the UK and its implications for school exclusion. Drawing on interviews with over 400 professionals, parents, and pupils in ten selected local authorities in England, Northern Ireland, Scotland and Wales, we find marked differences in the scale and nature of provision. These differences reflect the UK's diverging political economies of education. England's provision reflects its preference for quasi-market mechanisms. Scotland's reflects a commitment to inclusive education. Wales supports public provision but bears the legacy of historic control by England, while Northern Ireland's landscape is almost entirely publicly provided. The data suggest that the scale and diversity of alternative provision does not reduce school exclusions. England has the highest rates of exclusion and the greater number and diversity of providers. Scotland has lower rates of exclusions and fewer providers. It may even be that the availability of alternative provision creates its own demand. However, the relationship between exclusion rates and alternative provision is not straightforward, nor are its implications for educational parity. The paper concludes by arguing there is a pressing need for research on the opportunity costs of alternative provision for young people and the public sector.