Spatial data sets are most useful in the support of decision making, management of space, performance of government and business, etc., when integrated in governmental information infrastructures (architectures). This implies availability of well-maintained links between spatial data sets and other basic or key data sets, for example, on addresses, persons, companies, buildings, land rights, etc. Integrated and interorganizational value chains, business process management, and reduction in administrative overheads can be introduced based on new business models. In general, the resolution of problems in society requires more information than provided from one single data set, and this is equally true for problems with a spatial concept. It is evident that this type of data provision is complex in cases where data are stored at a variety of locations and in data models specifi c to their application domains. In this chapter it is argued that an effective infrastructure can be achieved solely by the use of authentic registers (or “key registers”) to store key data that are available for integration and multiple use.