Getting from Terminal T4 to T4S:
Regardless of the terminal assigned for your flight (T4 or T4S), access is always via T4 or Terminal Building. Both buildings are located at the north end of the airport, one opposite the other, and are connected by an underground automated people mover (APM).

Connections from Terminals T1, T2 and T3 to T4 and T4S, and vice versa:

• Internal connection: bus for transit passengers.
  If you are in transit and checked your luggage in at the departure airport, you can use this free service to get around the airport. It stops at all terminals: T1, T2, T3, T4 and T4S.

• External connection: free AENA shuttle buses.
  The buses operate 24/7 with departures from Terminals T1 and T2 direct to Terminal T4.