I have an iPhone 3G 8GB that I am going to sell, having upgraded to an iPhone 4. At the moment it is locked to Tesco mobile – they will unlock it for free in a month (or £20 now but the instructions won’t be straight-away apparently), but I figure that I will get a better price if I sell before Christmas, so am planning to sell it ASAP.
I was considering using an online unlock service, but from what I understand, an unlocked phone can lock again following an Apple software update. Therefore, I was thinking of selling it locked to Tesco, then the new owner can deal direct with an unlocking site (- that then guarantees to clear up any issues relating to future updates).
Could anyone advise on this? Am I right? Would it be better to unlock now? Who to use, etc.?