Method for initializing and de-initializing a mobile vehicle device suitable for collecting fees of a vehicle, which mobile vehicle device is designed to provide vehicle data (f i) of the vehicle and/or at least one item of information (b i,j) dependent on vehicle data (f i) for wireless transmission, by way of at least one first communication interface (265, 267) of the mobile vehicle device, to at least one registration device, arranged outside the vehicle, of at least one vehicle fee system, comprising: - transmitting the vehicle data (f i) of the vehicle to the mobile vehicle device, - at least temporarily storing the vehicle data (f i) in a memory area of a data memory of the mobile vehicle device and - releasably fastening the mobile vehicle device in the vehicle, characterized in that, - in order to transmit the vehicle data (f i) to the mobile vehicle device, at least one transponder (300, 310, 320, 330) that is fastened on the vehicle outside the mobile vehicle device and that provides the vehicle data (f i) is activated, and - transmitting the vehicle data (f i) to the mobile vehicle device comprises reading and receiving the vehicle data (f i) provided by the transponder (300, 310, 320, 330) by way of a reading apparatus (205, 215, 225, 235) that is included within the mobile vehicle device or is at least temporarily connected thereto in order to exchange data, wherein - i) the transmission of the vehicle data (f i) of the vehicle to the mobile vehicle device and/or ii) the storage thereof in a memory area of the data memory is triggered as a sufficient condition or is made possible as a necessary but insufficient condition by fastening the mobile vehicle device in the vehicle, and wherein putting the data memory into a state that corresponds to the absence of vehicle data (f i) in the data memory is triggered as a sufficient condition or is enabled as a necessary but insufficient condition by detaching the mobile vehicle device from the vehicle. - transmitting the vehicle data (f i) of the vehicle to the mobile vehicle device, - at least temporarily storing the vehicle data (f i) in a memory area of a data memory of the mobile vehicle device and - releasably fastening the mobile vehicle device in the vehicle, - in order to transmit the vehicle data (f i) to the mobile vehicle device, at least one transponder (300, 310, 320, 330) that is fastened on the vehicle outside the mobile vehicle device and that provides the vehicle data (f i) is activated, and - transmitting the vehicle data (f i) to the mobile vehicle device comprises reading and receiving the vehicle data (f i) provided by the transponder (300, 310, 320, 330) by way of a reading apparatus (205, 215, 225, 235) that is included within the mobile vehicle device or is at least temporarily connected thereto in order to exchange data, wherein - i) the transmission of the vehicle data (f i) of the vehicle to the mobile vehicle device and/or ii) the storage thereof in a memory area of the data memory is triggered as a sufficient condition or is made possible as a necessary but insufficient condition by fastening the mobile vehicle device in the vehicle, ii) the storage thereof in a memory area of the data memory is triggered as a sufficient condition or is made possible as a necessary but insufficient condition by fastening the mobile vehicle device in the vehicle,