In both tort and contract, the addition of a public body as a party to proceedings typically superimposes complex, policy-based considerations onto a given claim. This premise remains true in the context of a claim concerning restitution for unjust enrichment. The recent case of SurreyCountyCouncil v NHS Lincolnshire  EWHC 3550 (QB) concerned a successful unjust enrichment claim by one public body against another to recover costs of specialist care for an autistic man which, although statutorily required, were not provided. The facts of the case and its decision provide fertile ground to explore the complexities that arise in an unjust enrichment claim where a public body is party to the proceedings. In particular, the reasoning of Thornton J encourages analysis of the policy-based reasons for restitution and the utility of the change of position defence in the context of an unjust enrichment claim against public bodies.