This Practice Note describes the key commercial provisions in a standard gas sales agreement (GSA), a specialised form of commodity sale and purchase agreement wherein the seller undertakes to make gas available to the buyer and the buyer agrees to pay the seller in return for the availability of that gas. In particular, this Practice Note considers the terms of the Association of International Energy Negotiators (2006) and European Federation of Energy Traders (version 2.0, 11 May 2007) model form gas sales agreements (GSAs).