A portable data carrier (1) comprising a contact pad (2) according to ISO 7816-2 as a physical interface for communication has a contactless interface device (7) for communication with an end device according to a contactless communication protocol via a preset activated contact assignment of the contact pad (2), and at least one contact interface device (4, 5, 6) for communication according to a contact-type communication protocol via a further activated contact assignment of the contact pad (2). In an initialization phase of the data carrier (1) a control device (3) activates a second contact interface device (4, 5, 6), besides an already activated contact interface device (4, 5, 6), only when the former does not use a contact assignment of the contact pad (2) that collides with the contact assignment of the contactless interface device (7). The contactless interface device (7) is activated as a second interface device if the preset contact assignment of the contactless communication protocol does not collide with the contact assignment of the already activated contact interface device (4, 5, 6).