When you deactivate the PIN at the third-party station, the foreign node sends a PIN deactivation messages to the home node. This informs the home node that the PIN was deactivated and deletes the station number of the foreign station in your memory.

The mobile user should not be identified at multiple stations simultaneously because the status of the home station can only be updated at one foreign station. If the mobile user is identified at a second foreign station, an identification existing at another station should be automatically deleted. To do this, the home station sends a PIN-deactivation message to the first foreign station where PIN deactivation is performed. If the connection between the home and foreign system breaks down, the first identification remains intact because the deactivation message to the foreign station is not repeated. The PIN remains active at the foreign station. Consequently, the mobile user cannot be sure that the first identification was automatically deactivated when entering the PIN at another station. The home data can only be updated at the station where the mobile user was last identified because only this station is known to the home station.