VEHICLE DOOR UNLOCKING SYSTEM AND METHOD

A vehicle door unlocking system of the present disclosure includes an in-vehicle device installed in a vehicle and an external device installed outside the vehicle. The in-vehicle device acquires unlocking information externally given to the vehicle to unlock the door without a key operation and outputs an unlocking command for making a door locking device unlock the door. The external device acquires the unlocking information defined by a user of the vehicle from the in-vehicle device or a portable terminal of the user and stores the unlocking information as an emergency unlocking information. The external device sends a door unlocking permission signal of the door to the in-vehicle device to make the in-vehicle device output the unlocking command when the unlocking information given to the vehicle and sent from the in-vehicle device coincides with the emergency unlocking information.