Originally Posted by
TGarza
If the iPhone is carrier unlocked, you can change the carrier selection from automatic to manual. This would prevent the international roaming unless you specifically select the carrier.
Our iPhones were carrier unlocked when we had a problem with an iPhone on our last international trip. The Carrier option appears below the hotspot option once the iPhone is carrier unlocked for iOS 10.3.3
Doesn't have anything to do with carrier unlocking. The presence of that menu item is controlled by the SIM in the phone. Verizon, for example, hides it if you're in the US and shows it if you're outside the country.