Abstract: The invention relates to an electronic transaction method. The method comprises carrying out an initiation communication between a terminal device and a mobile device, and carrying out an electronic transaction on the basis of the initiation communication between the terminal device and the mobile device. The initiation communication between the terminal device and the mobile device is a unidirectional communication in which initiation data is transmitted from the terminal device to the mobile device. The invention furthermore relates to a terminal device for use in an electronic transaction method, and to a transaction application for a mobile device for use in an electronic transaction method.