Originally Posted by
jonu
Wait, does turning off "Data Roaming" also turn off voice and SMS roaming? Because this would do the trick! I assumed that it didn't include control over voice and SMS since they went out of the way to call it "Data," the the "Cellular Data" switch clearly leaves the phone connected for voice and SMS.
No, you have to force it to use a network that your carrier doesn't have a roaming agreement with.