NSDI subjects participate in implementation and maintenance of NSDI by maintaining spatial data and services, and on demand make available the information on spatial data for which they are responsible. NSDI subjects are (NN 16(2007):
- Public administration bodies,
- Bodies of regional and local self-government,
- Public systems fully or predominantly owned by the Republic of Croatia,
- Physical and legal persons that have been entrusted with managing spatial data by competent authorities and regimes from this articles,
- Physical and legal persons that use data and services within the scope of NSDI and provide public services based on that data.