To tackle complex societal challenges, governments need to make evidence-based decisions and need the best available data as input. Much of the relevant data (e.g. user location data) is now in the hands of the private sector, which means governments increasingly resort to purchasing data from the private sector. This poses several challenges, such as data quality and lack of control, especially for local authorities with limited IT and procurement capabilities. This project develops a unique dataset of data purchasing ‘cases’ that can be used to map the state of play as regards data purchasing.