Is it possible to transfer a SIM card from an active TMobile ONE line, with a fully paid off phone, to a new and unlocked phone?
In other words, on one particular line, I have an old iPhone, but I just bought another (unlocked) and was wanting to put the SIM card into that phone. Would that be OK? Do I still need to call Tmobile if they're both iPhones? I have yet to try it, just wanted to make sure I wasn't going against any kind of agreement.
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