A mobile wireless communications device may include a near field communication (NFC) transceiver and a controller coupled with the NFC transceiver. The controller may be configured to receive tag data from at least one NFC tag when in close proximity thereto via the NFC transceiver, verify the tag data, and when the tag data is successfully verified, perform at least one device unlock operation. The controller may be further configured to determine whether the tag data should be changed based on a predetermined schedule, and if it is determined that the tag data should be changed, communicate with the at least one NFC tag to change the tag data.