One of the principal challenges to reaching targets of the Energy Transition (ET) is to improve the coordination between local authorities and regional governments with the aim to enhance decision-making process, coherence and consistency of the implementation of energy transition measures (ETM). ePLANET will meet this challenge by encouraging the digitalization of measures and plans enabling an interoperable ecosystem of data and tools supporting energy transition decision making, putting it into practice by the public sector. ePLANET builds on an existing infrastructure enabling massive data gathering, making the data and measures comparable and interoperable with existing local initiatives (CoM, Clean Energy for EU Islands Initiative) and regional/national plans, analysing this data and offering relevant results to key stakeholders. This will enhance decision-making -more informed, more transparent and faster decisions-, contributing to improved monitoring and verification schemes. Enabling harmonisation of plans and interoperability across the local and regional authorities to joint application of ETM favouring more efficient use of public spending. ePLANET is a three-year project that will develop a proof of concept over three regional pilots (Girona, Crete and Zlín regions) during the first half of the project, to ensure the correct deployment of developed tools and to fit the real needs of public authorities in the energy transition. The rest of the project will focus on extending and implementing the ePLANET tools and methodology across Europe. To ensure new regions and local authorities’ engagement, the project will leverage existing initiatives (CoM and ManagEnergy) in which the project partners have strong influence (ICLEI and FED in particular).