A communication system for implementing locking of a device (102) is described. The device (102) can be locked to a network service provider for a validity period. After expiry of the validity period, the device (102) can be automatically unlocked. In locked mode of operation, an integrated circuit (IC) card tool-kit (214) that is used for housing the IC card, is disabled in the device (102). During the validity period, the device (102) transmits an equipment identity number to the network service provider while initiating a request for communication. The network service provider dynamically allocates a subscriber identity number to facilitate communication process. After expiry of the validity period, the device (102) is unlocked automatically and the IC tool-kit (214) of the device (102) is enabled.