A large part of the necessary investments for sustainability transitions, especially to reach net zero and other environmental goals, must be made at the municipal level. In many European countries, however, there are no adequate financing mechanisms to support municipal actors. Against the background of current developments in sustainable finance and the EU-Mission for 100 Climate-Neutral and Smart Cities, the project aims at developing concrete, innovative and structural solutions together with relevant stakeholders in a series of workshops. This will be done exemplarily in Belgium, Germany and the Czech Republic, accounting for the different national framework conditions in the EU to the extent possible. In addition, the outcomes of the national level will be presented and discussed with the EU Commission to consider recommendations for better regulation at EU and national level to support the EU’s multi-level governance arrangements. The project is implemented in collaboration with the Fair Finance Institute, Starkmacher e.V., and the International Sustainable Finance Centre, funded by the BMUV within the framework of the European Environment Initiative (EURENI).