The PIN (Personal Identification Number) is a security feature of your SIM card. (The SIM card is a small postage-stamp sized card that fits inside your phone and contains information about your phone number).
Activating your PIN can prevent your mobile phone number from being used if your phone is lost or stolen. If you wish to activate your PIN or change it you can do so using the security feature on your phone. Please refer to your phone user guide for details.
If enter your PIN incorrectly three times, your handset will be locked and you will need a PUK (Personal Unblocking Key) code to unlock it. You will need to contact your Vodafone customer service team (using the telephone number on your monthly bill or 08700 700191) to obtain your PUK code. Do not try to guess your PUK!
Some mobile phones also have their own built-in PIN that can be activated to prevent unauthorised use of the phone.
Vodfone sim cards have a preset PIN of 0000. | 
