One variation of a method for controlling a reprogrammable payment card includes: at the payment card, establishing a wireless connection with a mobile computing device; receiving, over the wireless connection, a first magnetic sequence command corresponding to a first payment method, a first digital transaction credential corresponding to the first payment method, and a second magnetic sequence command corresponding to a second payment method; initiating a first mode; in the first mode, arming a controller within the payment card to drive a magnetic stripe emulator within the payment card according to the first magnetic sequence command; in the first mode, activating an integrated circuit within the payment card to broadcast the first digital transaction credential; and in the first mode, disabling operation of the magnetic stripe emulator and the integrated circuit in response to failure of a wireless connection with the mobile computing device.