This flagship report provides in-depth surveys and analyses of the quality of electricity and gas supply across Europe with associated recommendations for good regulatory practices to maintain a good level of continuity of supply, voltage quality, and commercial quality for customers across Europe. The report, for the first time jointly written by CEER and the Energy Community Regulatory Board (ECRB), compiles data from respondents from CEER Members and Observers and Energy Community Contracting Parties, covering a total of 39 countries. Since 2001, the Council of European Energy regulators (CEER) has produced six Benchmarking Reports on the quality of supply of electricity and, since 2016, of gas as well.