So I do not see much risk, but I agree that the safest way is to test another SIM card. 06-13-2013 12:02 Likes 0 3.6 planoman Remember that there is no need to be an active SIM from T mobile. You can also use this feature to replace the version software with a downloaded version of the OF1 software. Unlocked Phones San Francisco. Here how to rotate and change the uploader. Another way to check if the phone is locked or not is by inserting a SIM card from an operator other than the carrier you originally purchased from the phone. You must first insert the SIM card to the scheduled carrier and start the phone so that it can register the SIM card before you can use the phone in another part of the world. Android manufacturers usually also sell their devices on their own websites, and if you looking for the unlocked models of their devices, I find them next to the car versions. Galaxy S4, Galaxy S5 and Galaxy Note 3 are regionally secured phones, which means you can only use them in the world area for which they are intended. You must use the device in the sprint network for fifty days. The contract has been terminated, or your rent has been paid on the device, keeping an account in good condition, and of course, the device can not be reported as stolen or missing. The legacy of a fragmented 3G market is still alive, and although LTE is available in most parts of the country at this time, 3G as a return is still important to most consumers, and some unlocked devices have no support for older bands. If you are a Verizon customer with a recent Verizon smartphone, the GSM part (if any) is probably already unlocked based on an agreement that Verizon Wireless has with the US government. Or maybe you bought a phone online and you want to know if it linked to a particular network or want to be safe. It is unlocked to sell it.