Originally Posted by whosloosin92

The AT&T card in the US phones is one specifically for the iPhone service right? So wouldn't he need an O2 card specifically for the iPhone service? Forgive me if im wrong i do not know how the UK services are set up.

It has been demonstrated that you can jailbreak and then activate UK iPhones to use ANY O2 sim (also pre-pay) and German iPhones to use ANY T-Mobile sim.

Now, the question is whether there is a "regional" lock related to the country where the phone was purchased or not (in other words, if you can use this trick to use a german T-Mobile sim, for example, on a UK iPhone).

Originally Posted by DecksTerrorT

In the o2.plist file there is a valid sim section, maybe I am chasing a red herring.

I wonder if there is a way to work out how the numeric values in the plist are generated.

Sorry if I carry on with my assumptions, but wouldn't it be easier to restore the phone and go through the whole jailbreak/activation again (this time with the o2 sim) to see if it works?

I will, tomorrow.

The valid SIM values just define the MCC+MNC combinations, i.e. for O2-UK it would be 234-10 which is one of the values you will find.