Mobile device with multiple SIM cards

The invention relates to a mobile communications device comprising a mobile station (103) using a SIM card (101a; 101b; 101c; 101d) to a mobile network (102) is connectable. Further, a with the mobile station (103) connectable multiplexer (106) for receiving a plurality of SIM cards (101a; 101b; 101c; 101d) is provided, wherein the multiplexer (106) via first switch means has (via each having a SIM card 101a; 101b; 101c; 101d) is connectable to the mobile station (103). Furthermore, the device comprises a second switching means which is designed to switch off the mobile station (103), while a SIM card (101a; 101b; 101c; 101d) separated from the mobile station (103) and another SIM card (101a; 101d) is connected to the mobile station (103); 101b; 101c. By the mobile station to turn off (103) is achieved in particular that a shutdown procedure to shut down a SIM card used previously (101a; 101b; 101c; 101d) is performed, so that SIM cards (101a; 101b; 101c; 101d) securely can be changed.