Abstract: The present invention relates to a method of roaming for a terminal (10) connected to a first mobile telephone network (1a), the method being characterized in that it comprises the implementation by processing means of a subscriber identification card (11) of the terminal (10) of steps of: (a) detection of a deficiency affecting the data service of the first network (1a) to which the terminal (10) is connected; (b) inscribing of said first network (1a) for which a deficiency of the data service has been detected in a list of prohibited networks (FPLMN) that is stored in storage means of the subscriber identification card (11); (c) selection of a new network (1b, 1c) and connection of the terminal (10) to said new network (1b, 1c); (d) removal of said first network (1a) from said list of prohibited networks (FPLMN). The present invention relates moreover to a subscriber identification card and to a terminal.