I Just have bought the I Pad 3 with 4G on e bay from someone who has had it for a couple of months.
It came with a three sim on a pay as you go contract.
I want to use a different carrier, how do I know if it is locked to three and if I can use another sim like T Mobile in my I Pad ?
Also any way of telling how much money is left on the sim ? I didn't get a card or anything with it to top up.