A method and system of restoring a functionality of a mobile user device. A lock screen is displayed on the display of the user device. An international mobile subscriber identity (IMSI) of a subscriber identity module (SIM) card presently installed in the user device is determined. The IMSI is sent to a Remote Recovery Server (RRS). A message is received from the RRS indicating whether the IMSI is authorized for the user device and whether an account of the user device is replenished at least in part. Upon determining that the IMSI is authorized for the user device and the account of the user device is replenished at least in part, at least one function that was previously restricted is restored.