A mobile device, through the use of an NFC subsystem, may determine holster-proximity information, i.e., whether the mobile device is near to (including in) a holster or out of, and away from, the holster. The holster-proximity information may be used by the mobile device to enter into a user-inactive mode. Such entry into a user-inactive mode may involve disabling user interface components, such as input devices and output devices. In particular, the holster-proximity information may be used by the mobile device to disable the keyboard, that is, prevent presses on keys in the keyboard from being recorded. Such disabling may be considered of particular importance when the mobile device is going into and coming out of the holster.