All S-Bahn train lines and buses can be used for journeys between the terminals.
The S9 and S45 S-Bahn train lines connect the stations of the Terminal 5 of BER, Wassmannsdorf and Terminal 1-2, making it possible to travel between terminals in just 8 minutes approximately every 10 minutes.
VBB Travel Information
It’s easy to transfer between Terminals 1+2 and 5: just click on the direction you want to travel in and you will get the train and bus connections you need.