In order to connect to the cellular network abroad, you’ll be in what is known as ‘roaming’ mode because you are no longer on your primary carrier’s network.

Family racks up $13,000 in iPhone data roaming fees while overseas, but says phones were on airplane mode A family says it was wrongly billed $13,470 for using data overseas.

Prohibitively high mobile data roaming charges are killing mobile worker productivity and people are afraid to turn on their cellular devices," said Evan Kaplan, chief executive officer at iPass.

T-Mobile customers are now roaming on US Cellular’s network after the recent acquisition, boosting coverage in many rural areas, especially across the Midwest.