In this video:

You navigate to ProPlanner via a URL consisting of your customer name, e.g.: name.proplanner.eu. On the login screen, you will always have to select the Business Unit where you want to log in. 

What does this mean? 

The selection you make on the login screen automates certain actions, like making a new Contract from your location. 

You will still be able to consult vehicles and fleets from the other Business Units that you have access to.