Since the enactment of the UK’s Subsidy Control Act, its public authorities, the CMA’s Subsidy Advice Unit, and its courts have had to grapple with both the theoretical and practical implications of complying with and enforcing the Act. This article discusses these actors’ different roles. It examines how the reporting function of the Subsidy Advice Unit differs from the role of the European Commission; the Competition Appeal Tribunal’s judgment in the Durham Waste Management case on the first application for review of a subsidy decision under the Act; and the evidentiary burden imposed on public authorities. The article also provides insights into the four steps underpinning the assessment of a subsidy, drawing upon the 22 reports published by the Subsidy Advice Unit in the first year of the Act coming into effect. Finally, this article concludes by reflecting on these developments and the future of UK subsidy control. Keywords: Subsidy Control Act; Durham Waste Management; Subsidy Advice Unit; UK.