1. Find "SIM card security"
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Security and privacy.
Press More security settings.
Press SIM card security.
2. Turn use of PIN on or off
Press the indicator next to "Lock SIM card" to turn the function on or off.
Key in your PIN and press OK.
If an incorrect PIN is entered three times in a row, your SIM will be blocked. To unblock your SIM, you'll need to key in your PUK. You can get the PUK by calling customer services on 191 from a Vodafone mobile phone. If you're using a land line, you need to dial 03333 040 191. Please note: If you key in the wrong PUK ten times in a row, your SIM will be blocked permanently. In this case, you need a new SIM from Vodafone.
3. Return to the home screen
Press the Home key to return to the home screen.