The concept of Mobility-as-a-Service (MaaS) has the potential to help break away from the current automobility system of private car ownership towards a more sustainable 'post-car' system. While technology undoubtedly plays an important role in the development of MaaS schemes, coordinating the various stakeholders, from different levels of decision-making, seems to be an equally, if not even greater challenge. Building on a case study that focused on the development of the very first MaaS commercial solution in the Helsinki Metropolitan Area, this paper uses the multi-level governance (MLG) analytical framework to discuss which governance mechanisms are most likely to support the full realization of the MaaS potential. Findings indicate that while Type II governance processes (horizontal development of a MaaS network, unfolding of several MaaS initiatives in parallel, informal lobbying from local government) undoubtedly played a role in the emergence of the solution, it is mainly thanks to Type I mechanisms (strong visions from public authorities, development of a dedicated legislation) that MaaS could finally move forward in the Finnish capital region, and exit the institutional dead-end in which it was trapped. By shedding light on the governance of Mobility-as-a-Service, this paper contributes to the growing MaaS literature that has paid so far little attention to the nuts and bolts of MaaS development, and contributes in further using the MLG in transport studies. The paper ultimately concludes by highlighting the need to conduct more research on the governance of MaaS in order to ultimately develop a more holistic understanding of the role that public authorities are playing in its development.