The Handbook on Cross-Border Energy Communities (CBECs) offers a comprehensive overview on how to establish and manage energy initiatives that span national borders within the European Union. It is aimed at empowering local actors, policymakers, and stakeholders to navigate the legal, technical, and administrative challenges unique to CBECs, while emphasizing their contribution to the EU's energy transition and cohesion objectives. CBECs present numerous benefits, including economic efficiencies, job creation, enhanced energy independence, and reduced carbon footprints. However, they face significant challenges. The Handbook provides practical information and highlights good practices, such as "Calorie Kehl-Strasbourg" and "Zusamme Solar! Colmar”, which demonstrate successful governance, innovative financing, and collaborative technological approaches that can serve as inspiration for new cross-border projects. By addressing existing barriers to cross-border cooperation in this field and implementing its recommendations, policymakers and stakeholders can unlock the potential of border regions, transforming them into key contributors to a sustainable and interconnected energy future for the EU.