This guide outlines how Citizens Advice monitors the activities of energy suppliers in the changing energy retail market. The document details the ongoing and reactive monitoring processes employed to assess supplier performance and address emerging issues. Citizens Advice engages with suppliers and Ofgem to ensure compliance and rectify service failures. It describes the tripartite process involving regular meetings with Ofgem and the Energy Ombudsman to share intelligence and identify trends. The guide emphasizes the importance of providing consumers with information to make informed decisions, including the publication of performance ratings for suppliers. It also explains the data sources used for monitoring, such as anonymized consumer service data and direct complaints from suppliers. The document highlights the escalation process for unresolved issues, ensuring that serious concerns are addressed promptly. Overall, it serves as a comprehensive resource for understanding the monitoring framework and practices in place to protect energy consumers.