Have to disagree with the previous rating.
I found my experience with them very rewarding. I wanted to unlock my iPhone 4 running 4.0.1 software and was able to do so. They don't claim to sell their own software like many other websites and clearly state what software versions they can unlock.
My friend has the latest version of software 4.2.1 on her phone and contacted iphone4unlock.co.uk to see if they could unlock it. Within minutes they responded and told her no unlock was available for that software and any website claiming to be able to do it was simply lying. Foolishly she took the plunge with another website and is now fighting to get her money back, £39.99.
My review of iphone4unlock.co.uk is positive and if you have any queries i suggest you simply contact them first and they will give you an honest answer.
***** 5 Stars