I have an wifi and cellular iPad Air 2 that I purchased directly from Apple. Because I have Verizon as a wireless carrier, I had to swap out the Apple SIM card with a Verizon sim card. If I leave Verizon, I can put the Apple SIM card back in for use on other networks. I'm trying to get away from Verizon and have been interested in T-Mobile. However, T-Mobile's website keeps telling me that my iPad is not supported and I'll have to buy a new one. Why would I have to buy a new iPad? Couldn't I just replace the Verizon SIM card with T-Mobile's? I would have to do the same thing with my Galaxy S5 and the T-Mobile's website says it's supported. Buying a new iPad barely six months after purchasing one is definitely a deal breaker for switching carriers. I want to verify this before I look elsewhere.
It'll work in most areas. The warning is kind of obscured.
It supports everything except band 12. In some areas you will not get LTE and that's why it says it's not compatible. Also you might want to ensure your iPad 2 is unlocked(i know their phones are but not sure on tablets).
Manage your T-Mobile account