The recast of the Electricity Directive (EU) 2019/944 in the Clean Energy Package entitles the European Commission to adopt implementing acts specifying interoperability requirements and non-discriminatory and transparent procedures for access to data. Preparatory work is already ongoing. In this policy brief, we argue that the acts should be ambitious in addressing the multiple dimensions of interoperability and that we can draw inspiration from existing experience with interoperability in the electricity and the healthcare sectors. We also provide governance recommendations. First, different multi-dimensional interoperability frameworks exist. While they agree that full interoperability can only be achieved if all dimensions are addressed, they do not agree on either the number of dimensions or on labelling them. We do not propose an additional framework but identify commonalities across the frameworks that need to be addressed to achieve full interoperability of energy services within the Union. Second, experience shows that different use cases can inspire different solutions. We focus on the North American Green Button initiative for utility customer data and ENTSO-E’s experience in supporting network code requirements for the exchange of market and network data. Moreover, experience with interoperability in healthcare is very advanced and can serve as an inspiration for energy, especially regarding interoperability testing and governance. Third, governance is a key issue in achieving interoperability. The existing governance mainly covers stakeholder dialogue and European standardisation. We provide ideas on how to use the EU interoperability acts to step up these efforts. In addition, we think governance should be extended to include formalisation of best practices, implementation monitoring and reporting, and interoperability testing. This governance could be taken on by a new EU entity.