Phoned up Voda this morning to unlock my phone as I'm going away. They did it for free even though my contract is still less then 12 months in.
Did some research and found the following info on a Vodafone forum:
"If you got the phone with a contract the Network Unlock Code (NUC) will be free of charge, regardless of its age, as all new contract phones are now dispatched unlocked.
If the phone is a PAYT handset over 12 months old the code will also be free of charge.
If it's a PAYT handset that's less than 12 months old a charge of £19.99 including VAT would apply. The £19.99 will need to be credited to your phone before you apply for the code. Once the NUC has been issued the charge will be debited."