Many people smartly protect their SIM cards with a PIN number, because this protects intruders from using your SIM card in their own phone; they can peruse through your contacts and effectively steal your cellular and/or data service. However, instances inevitably arise where you forget your PIN number, or your SIM card is simply unresponsive. Fortunately for such cases, AT&T can provide you an unlock PIN for your SIM card and allow you to use your phone with full functionality once again. Tips Warnings Writer Bio

How to Get an Unlock Pin for an AT T SIM Card - 56