The only real way to unlock an iphone is to do it via the network. If you are already a subscriber and have used the orange/EE/T-Mobile SIM in the phone for at least 6 months, then happy days - fill out
this form, pay your money and wait a century
If you want to unlock an Orange iphone, and aren't an EE/T-mobile/Orange subscriber, then you will need to do what I did and grab a PAYG EE SIM and use it in the phone for at least 6 months, otherwise they won't unlock it for you.
You don't have to use it constantly but at least stick it in every now and then and make a call/text. And then once your penace is done, fill out the form on the EE website and pay the unlock fee (which is now under £10). Be prepared for them to 'lose it down the back of the sofa' until you beat a path down to their door asking why 'owt has happened.