Method for checking an authorisation of a mobile unlocking device, comprising: determining a position of the mobile unlocking device on the basis of a signal from the mobile unlocking device, transmitted via a cellular network, wherein the signal satisfies the NB-IoT standard of the 3rd Generation Partnership Project, wherein the mobile unlocking device is a smartphone, wherein the signal is transmitted as a result of communication between the object to be unlocked and the mobile unlocking device, and wherein a communication device of the mobile unlocking device is changed to an operating state from the Power Save Mode according to the NB-IoT standard of the 3rd Generation Partnership Project for communication with the cellular network as a result of the communication between the object to be unlocked and the mobile unlocking device, wherein the communication device is returned from the operating state to the Power Save Mode according to the NB-IoT standard of the 3rd Generation Partnership Project following the transmission of the signal via the cellular network; comparing the position of the mobile unlocking device with a position of the object to be unlocked; and establishing the authorisation of the mobile unlocking device if the position of the mobile unlocking device is at a distance from the position of the object to be unlocked which is smaller than a predefined distance, wherein, if the determination of the position of the mobile unlocking device on the basis of the signal is not possible or the comparison of the position of the mobile unlocking device with the position of the object to be unlocked is not unambiguous, the method further comprises the following: determining a movement trajectory of the mobile unlocking device on the basis of at least two further signals from the mobile unlocking device, transmitted via the cellular network, wherein the at least two further signals were transmitted chronologically before a time of a communication between the object to be unlocked and the mobile unlocking device; comparing the movement trajectory of the mobile unlocking device with the position of the object to be unlocked; and establishing the authorisation of the mobile unlocking device if a course of the movement trajectory relative to the position of the object to be unlocked satisfies a predefined criterion. determining a position of the mobile unlocking device on the basis of a signal from the mobile unlocking device, transmitted via a cellular network, wherein the signal satisfies the NB-IoT standard of the 3rd Generation Partnership Project, wherein the mobile unlocking device is a smartphone, wherein the signal is transmitted as a result of communication between the object to be unlocked and the mobile unlocking device, and wherein a communication device of the mobile unlocking device is changed to an operating state from the Power Save Mode according to the NB-IoT standard of the 3rd Generation Partnership Project for communication with the cellular network as a result of the communication between the object to be unlocked and the mobile unlocking device, wherein the communication device is returned from the operating state to the Power Save Mode according to the NB-IoT standard of the 3rd Generation Partnership Project following the transmission of the signal via the cellular network; comparing the position of the mobile unlocking device with a position of the object to be unlocked; and establishing the authorisation of the mobile unlocking device if the position of the mobile unlocking device is at a distance from the position of the object to be unlocked which is smaller than a predefined distance, wherein, if the determination of the position of the mobile unlocking device on the basis of the signal is not possible or the comparison of the position of the mobile unlocking device with the position of the object to be unlocked is not unambiguous, the method further comprises the following: determining a movement trajectory of the mobile unlocking device on the basis of at least two further signals from the mobile unlocking device, transmitted via the cellular network, wherein the at least two further signals were transmitted chronologically before a time of a communication between the object to be unlocked and the mobile unlocking device; comparing the movement trajectory of the mobile unlocking device with the position of the object to be unlocked; and establishing the authorisation of the mobile unlocking device if a course of the movement trajectory relative to the position of the object to be unlocked satisfies a predefined criterion. determining a movement trajectory of the mobile unlocking device on the basis of at least two further signals from the mobile unlocking device, transmitted via the cellular network, wherein the at least two further signals were transmitted chronologically before a time of a communication between the object to be unlocked and the mobile unlocking device; comparing the movement trajectory of the mobile unlocking device with the position of the object to be unlocked; and establishing the authorisation of the mobile unlocking device if a course of the movement trajectory relative to the position of the object to be unlocked satisfies a predefined criterion.