Hi i was needing to know if i can use my micro sim out of a galaxy s3 i have on contract with AT&T and use it in a iphone 4 gsm unlocked. i was also wondering will they charge me for swapping the sim card from one phone to the other?
They'll know that you've switched devices. Whether or not they'll charge, that I'm not entirely sure since I'm not an AT&T user, but all carriers will know eventually that you've switched to a device that's not the one on your contract.