INTERLINK aims to overcome the barriers preventing administrations to reuse and share services with private partners (including citizens) by developing a novel collaborative governance model that merges the enthusiasm and flexibility of grassroot initiatives with the legitimacy and accountability granted by top-down e-government frameworks. We believe that a solution incorporating the strengths of these two approaches will be able to overcome their individual limitations, namely lack of involvement of private actors, transparency and trust for “top-down” and lack of sustainability, accountability, and legitimacy for “bottom-up” initiatives. To enable this, INTERLINK will provide a set of digital building blocks, called “Interlinkers”, that implement the defined governance model and standardize the basic functionalities needed to enable private actors to co-operate in the delivery of a service (organization, communication, scheduling, monitoring, etc.). In this way, the new shared service will maintain the effectiveness of digital solutions adopted in grassroots initiatives to support self-organization and make collective decisions, and at the same time fulfill the technical and legal requirements necessary for adoption by Public Administrations (PAs). The INTERLINK multidisciplinary consortium will deliver the new governance model and Interlinkers within a technological framework and operational platform based on an open software system leveraging on mobile communications, facilitating the co-production of services between PAs and private stakeholders. The solution will be customised, deployed and evaluated on three use-cases within the partner PAs: the Italian Ministry of Economy and Finance, the Latvian Ministry of Regional Development, and the City of Zaragoza. Lessons learned in the three use-cases will be generalized to deliver a re-usable solution across Europe.