Abstract: A contactless transaction card is detachably connectable to an antenna provided on a flexible film having an adhesive coating or other carrier surface. An integrated circuit chip on the contactless transaction card includes leads for establishing an electrical connection with the ends of the antenna. The contactless transaction card and detachable antenna may be provided on a carrier card with the adhesive film adhered onto the card and the contactless transaction card either die cut into the carrier card or frictionally held in a recessed holder formed in the carrier card surface. In a preferred embodiment, a cover for a mobile telephone includes a holder for a contactless transaction card. An antenna may be either adhered onto the cover by the user or may be permanently provided on the surface of the cover.