The real estate register contains all properties (parcels of land and buildings, basic data in descriptive and illustrative form) in the entire urban area and thus serves to secure ownership of land.

Anyone thinking about buying or selling a plot of land or planning to build a house needs it, as do local authorities who plan land and energy suppliers who lay electricity or water pipes: the official property map.

This shows all plots of land with their boundaries and all buildings to scale. Without the official real estate map and the other official real estate cadastral records, such as owner data, there is no purchase agreement, no entry in the land register and no land-use planning.

The real estate cadastre therefore has two basic purposes:

It serves as an official register of land plots for proof of ownership in the land register.
It can be used as a basic information system for other areas of administration and business.
For the area of the city of Bonn, the data of the real estate cadastre is available in digital form for the entire area and all property and owner information is managed and kept up to date in the joint "Official Real Estate Cadastre Information System" (ALKIS).

In order to adapt the official geodata of the real estate cadastre to the further development of information technology and to make it more easily accessible, a uniform national standard with an XML-based exchange interface was created with ALKIS.

The respective local court is responsible for all matters relating to the land register. Information on entries in the land register, land register excerpts/printouts and inspecting the land register can be found at  Bonn Local Court (opens in a new tab).