The present disclosure is directed to a system and method for selectively switching antennas of transaction cards. In some implementations, a method includes physically interfacing a card with a mobile host device including a Graphical User Interface (GUI). The card executes wireless financial transactions independent of the mobile host device. User credentials used to execute financial transactions with retail terminals are stored. Information is presented through the GUI of the mobile host device. An antenna of the card is selectively switched between an activate state and an inactive state in response to at least an event.