What do I do if my phone asks for a PUK code?

The PUK (Personal Unblocking Key) code is needed when a security PIN number has been entered incorrectly three times. To request a PUK code, please contact your Vodafone customer service team using the telephone number on your monthly bill (call 08700 700191 if you are unsure). You should not attempt to guess your PUK code as entering an incorrect PUK code could permanently block the sim, causing you to lose all the data stored on it.