Abstract: Method and device for communication between an automobile vehicle and payment unit carried by a user in order to pay for an action carried out on the vehicle equipped with wireless communication elements (11) and the payment unit including at least one portable device equipped with wireless communication elements (22) for communicating with the vehicle via a wireless communication (A) and with a central server via a wireless communication (C) and an electronic payment card, the method including: equipping the payment card with wireless communication elements for communicating with the portable device via a wireless communication (B), equipping the payment card with storage elements, performing various steps for mutual recognition between the various elements of the device, and authorizing use of the payment card via authentication data for single use sent by the central server to the portable device then stored in the payment card.