This paper describes a Participatory design case study on how the reuse of existing data can support cooperative work of Third Sector Organisations in a local context. While many Third Sector Organisations collect data about their own services and local communities' needs, this data is rarely reused by the organisation or shared with others, due to a lack of resources and funding. To explore this issue, we have engaged in Participatory Design research with six locally based social organisations from Scotland. As an outcome of this research, the organisations have imagined the concept of the “Datashare” platform. This is a platform that would allow reusing and sharing of their data by exchanging it widely through the sector and beyond. The paper contributes to knowledge by bringing reflections on the role of the PD process in fostering open data culture for collaboration for Third Sector Organisations highlighting the potential impact of the designed solution.