This video shows how to unlocka smartphone to allow use of any carrier for any country as well. Soem smartphones that are purchased from phone carriers are carrier locked and using a different carrier SIM card will not work and instead it will come up with a network locked screen saying that the phone is not allowed to use the SIM card and that to use it, it requires entering the correct network unlock code to carrier unlock it. The smartphone carrier network unlock code is: 749052384703853. This can be done for many different phones no matter what carrier it is on. This should work if everything is done correctly. Once the code is entered, tap the OK button and the phone will verify the unlock code and if the code is right then it should come up saying the network is unlocked and any carrier should work with the phone now. To get the network lock page to come up, insert a SIM card that the phone is not allowed to use and then a message saying that the phone isn't allowed to use that SIM should come up and that you should be able to enter the unlock code. I hope that helped to use other carriers on the phone.