Hey guys, I'm new here. I know this question has been asked a few times, but I can never find the exact answer I'm looking for. I plan to buy a used or new iphone 4s and use h20 wireless on it. Will the h20 sim card activate my phone or do I need to use an at&t sim card? I know that h20 runs on the same towers as at&t so would it work? Thanks in advanced.