Funding an SDI is about guaranteeing the long-term financial security of an SDI, by obtaining and formalizing financing for the implementation and maintenance of the different SDI components. An SDI funding model provides the answer to the central question of where and how to seek funding for implementing and maintaining an SDI. Within an SDI often different funding models will be combined, as the selection of the most appropriate funding model will be linked to different activities and the associated costs. Costs of an SDI include both set-up costs (one off costs) and maintenance costs (yearly), of which certain costs need to be made for each data sets or each data provider and other costs for the infrastructure in general. The most commonly used SDI funding models are centralized government funding, decentralized government funding (e.g. for each data provider), partnership funding, funding through revenues, and government funding based on donor agencies or on European projects.
The shift towards open data and the adoption of open data policies had an important impact on the funding model of many SDIs, as governments and organizations no longer could rely on revenues from selling their data and had to look for other funding models. As a result, new pricing strategies are employed, such as the provision of fee-based supplementary services, such as advice or tailor-made products based on open data. Also freemium/premium models, in which a basic version of the dataset is offered as open data (freemium) but the full dataset is available for a fee (premium), were considered as an alternative approach. In many cases, the loss of revenues was compensated by other funding models, such as increased government funding.