One variation of a method for controlling a payment card (including a magnetic stripe emulator, a processor, and an input region) includes: 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 and a second magnetic sequence command corresponding to a second payment method; initiating a payment mode comprising a disable trigger; in response to selection of the first payment method through the input region, arming the processor to drive the magnetic stripe emulator according to the first magnetic sequence command in the payment mode; in the payment mode, dismissing selection of the second payment method through the input region; and in response to instance of the disable trigger, disabling operation of the magnetic stripe emulator.