Work package 3, led by dena, will get the target countries (Belgium, Spain, Ireland, Italy, Lithuania, Poland and Romania) ready to join the European biomethane/renewable gas trading system through the establishment of national renewable gas Guarantees of Origin (GoO) issuing bodies. It also addresses the integration of the existing national GoO issuing bodies of Estonia and Finland into the European network of GoO issuing bodies. The national biomethane registries (or national GoO issuing bodies) are expected to be „lighthouses” in their home countries, serving as knowledge bases and providing guidance and assistance to potential biomethane investors. This is especially important in those member states where there is no biomethane production yet or where the industry is still in its infancy. Having a national biomethane registry is essential to provide end consumers (which initially will be large gas consumers seeking the sustainability and competitive advantages of biomethane/renewable gas) with reassurance and confidence.