A system and method for providing a user interface that allows users to change the active line on which an outgoing call may be placed. In example embodiments, a direction to display a line selection menu on the call screen is received from the user, where the line selection menu is comprised of data identifying one or more of the multiple communication lines accessible at the mobile device. In response to the direction received from the user, the line selection menu is displayed on the call screen, and an input identifying a user-selected communication line is received. A display field in which data identifying the active line is displayed is updated accordingly.