A method for locking and/or unlocking a vehicle having an input device for a code on the vehicle, via which the vehicle can be locked and/or unlocked, involves requesting the code via a mobile device having a mobile number registered to the respective vehicle with a data server. After the request, the data server generates a current code and send this to the mobile device and to the vehicle. The code can then be input via the input device and compared to the code sent to the vehicle and, should they match, locking and/or unlocking of the vehicle is enabled.