I have an iPhone6. I have the international plan. I am in Italy. No problems with wifi but cannot get any data roaming or voice. I can't figure out why not. Any hints on settings or anything else?
IN settings - cellular, make sure roaming is set to voice and data.
Turn off phone by pressing sleep/wake button until turn off slider comes up, then slide off. Wait 2 minutes then turn back on by pressing the same button until the apple logo shows up.