The SIM card inserted in this iPhone does not appear to be supported
I've just got my son an iPhone for his birthday tomorrow and I brought a tesco mobile sim for his phone and I got told that this sim would work on the phone. However today I checked to see if it was working and it says 'The SIM card that you currently have installed in this iPhone is from a carrier that is not supported under the activation policy that is currently assigned by the activation server. This is not hardware issue with the phone. Please insert another SIM card from a supported carrier or request that this iPhone be unlocked by your carrier.'
So what do I do now? Do I have to get it unlocked?
iPhone 4, New phone