What is data roaming (hub)

Data roaming is your phone using a network that isn’t your home carrier, usually abroad. Carriers often charge a daily pass or a high per-megabyte rate for that.

Leave data roaming off on the home line if you are using a travel eSIM for data. Turn it on for the travel line, or the eSIM will look installed and still won’t load anything.

On iPhone: Settings, Mobile Service, choose the travel plan, and enable Data Roaming. Set Mobile Data to that plan and turn off Allow Mobile Data Switching if you don’t want the phone to fall back to your home line.