A:Answer This phone is listed as unlocked which means it can be used with many different carriers. Please check with your preferred carrier to ensure compatibility. It is designed for use within the US. You would need to check with the carrier regarding the use of other sim cards. If an issue happens in the US, the device would need to be repaired with our support team. Our support team is available via Twitter @LGUSSupport, Facebook https://www.facebook.com/LGUSA/ or you can give us a call at 800-243-0000. ^CP