hi there,
are 02 handsets unlocked to other networks?.
many thanks,
I have used O2 Handsets with Orange sim cards in the past but not sure about the latest generation of phones.
you’ll probably find someone down at the local market who can sort it for you, might be best to go in civvi’s tho 
Most phones these days are already unlocked. This is because most of the networks have found that every phone on the market can be unlocked no matter what security they build into it! For example when the iPhone was first released, it took only a few hours for the unlocking video was YouTube.
but once unlocked as soon as you upgrade the software the iPhone locks up and becomes a very expensive desk ornament.
As for the original question I know that the Carphone warehouse all of the phones are sim free.
hi it depends on the phone but please be carefull if you use market stools as there are loads of differant softwere out there and most market stools use **** softwear and it will mess your fone up in the future use a well known shop that way you get the back up and they cant aford to use **** softwear because of there reputation plus it all depends on how old the phone is , if its a new model it will be upto a couple months before they get good softwear to unlock and yes 99% of o2 fones can be unlocked to use on any network even 3g but you cannot get 3g fones to work on another network 3g is the company and not the network hope this helps
So don’t upgrade, or wait for the hackers to hack the upgrade. Why do I give a sh!t anyway? The iphone is an expensive desk ornament / penis extension / security blanket / unecesary want even when it does work. 