Since the beginning of 2000, the Joint European Torus (JET) has been used under the European Fusion Development Agreement (EFDA) as a user facility. In this framework, the UKAEA as 'Operator' maintains and operates the facility and installs enhancements on behalf of EFDA under contract to the European Commission. The experimental programme is proposed and implemented by the 'users', scientists and engineers on secondment form the European laboratories. These laboratories also supply equipment for enhancement of the facility. The overall programme is co-ordinated and managed by the EFDA JET Close Support Unit. There have since been five experimental campaigns. The historical rate of successful pulsing has been largely maintained. One major shutdown has been completed with substantial in-vessel and ex-vessel tasks, and various small enhancements have been installed. The first major enhancement is imminent. The UKAEA has an overriding responsibility for safety and for the environmental impact of the project, including management of waste. These responsibilities need to be reconciled with the Operation of the facility. This paper reviews the requirements and procedures for control of the interface between the Operator, the Close Support Unit and users, presents performance measures for key aspects, and summarises the experience of the UKAEA in the operation of JET.