The Novo Mercado de Gás (New Gas Market) reform programme is set to enhance the physical flexibility of the gas system, enable gas to be delivered more quickly, foster competition and facilitate the integration of a higher share of intermittent renewables into the Brazilian energy system. In the longer term, an open, competitive gas market can more easily adapt to a multi-gas system that includes and deploys low-carbon gases. At the request of the Brazilian government, the International Energy Agency (IEA) has been providing technical advice based on international experience to inform and shape the country’s gas market reform programme from day one. This current white paper follows the report “Towards a competitive natural gas market in Brazil: A review of the opening of the natural gas transmission system in Brazil”, published in September 2018. It aims to share best practices from Europe in terms of gas market design and reforms, including commercial and practical implications. This white paper includes a section on the role of natural gas and low-carbon gases in Brazilian clean energy transition.