This paper analyses the main regulatory obligations imposed on traditional taxis, the justifications behind them and how these have been impacted by the emergence of new players. Its objective is to look at the potential evolution of the current regulatory framework and at the potential challenges National Competition Authorities may experience in their enforcement activities. It was prepared as a background note for a discussion held at the OECD in June 2018 on Taxi, Ride-sourcing and Ride-sharing Services.