["Journal of Law and Society, Volume 48, Issue 3, Page 434-454, September 2021. ", "\nAbstract\nTrust is a central concept in the regulation of public services. Two different models of trust can be distinguished, involving the creation of either substantive credible commitments or institutions to promote more collaborative relations. In this article, the differing implications of these two models are assessed through an examination of failed United Kingdom examples of the use of contracts for the provision of public services: the procurement of passenger rail services by means of franchises and the contracting out of a major part of the probation services. It is suggested that their problems can largely be explained through a failure to recognize the second model of trust in contractual provision, and possible institutional alternatives that might do so more fully are explored.\n"]