JAO S.A., or the Joint Allocation Office, is a central service provider for European electricity markets, primarily the Transmission System Operators (TSOs). Established to facilitate cross-border electricity trading, JAO plays a crucial role in the allocation and financial settlement of transmission rights to manage congestion on interconnectors between European countries. As a collaborative effort among European TSOs, JAO aims to enhance market integration and foster a more competitive and unified European electricity market. Its services are pivotal in ensuring efficient electricity trading across borders, thereby contributing to the reliability and sustainability of Europe's power supply.