The directives oblige TSOs to have a supervisory body which can take decisions with a significant impact on the value of the assets as well as implement compliance programmes in order to ensure a non-discriminatory conduct \[art. 20, 21 Dir. 2009/72/EC (electricity) and art. 20, 21 Dir. 2009/73/EC (gas)\]. \\
Currently, 42 European TSOs are part of the European Network of Electricity Transmission System Operators ENTSO-E: https://www.entsoe.eu/
In return for providing access to the transmission grid, the TSO receives network access tariffs from the users.