The subscriber identity module, or SIM, card is the small card in your mobile phone that provides the phone with its network ID. It is the SIM card that allows phones to be locked and unlocked for individual use and provides the network service provider with the information necessary to allow the phone to function on a network. If your phone or SIM card has been damaged or is malfunctioning, it may be necessary to retrieve the SIM card’s number before support representatives can assist you in fixing the problem. Tips Writer Bio
