The 9th ERRA Water Regulatory Training Course, hosted by the Regulatory Authority for Energy, Waste, and Water (RAAEY) of Greece, brought together 31 participants, including 18 from Greece and 13 from other regulatory authorities in Europe and beyond. The course, conducted in a hybrid format, offered both in-person and online participation. Over three days, participants delved into key aspects of economic regulation in the water utility sector. The training covered the principles of regulation, licensing, tariff setting, customer protection, and benchmarking. Through case studies and team assignments, participants applied theoretical concepts to real-world challenges faced by water utility companies, providing practical insights into the sector's regulatory complexities.