Should you allow mobile data switching on an iPhone overseas?

Install from the saved order email on steady, working Wi-Fi after arrival. In Settings > Mobile Service/Cellular/Mobile Data, open Mobile Data, select the travel eSIM and turn Allow Mobile Data Switching off. The wording varies with the phone’s region and software.

Then open the individual lines’ settings: keep data roaming off on the Australian line unless you deliberately use its roaming service, and follow the order email for the travel line. Some travel offers need roaming on; a local service can require it off, so this isn’t one switch to set identically on both lines.

Apple’s dual-SIM guidance explains that the iPhone uses one mobile-data network at a time. Allowing switching can let it change the data line in supported circumstances, including certain call situations. That can be useful for some domestic arrangements, but it isn’t the behaviour we’re aiming for when keeping travel data on a deliberately chosen line.

Turning switching off doesn’t turn off the Australian number or make its calls, SMS, voicemail or Wi-Fi Calling free. Those services keep the home carrier’s overseas rules. If you want the home line active for bank messages, settle those costs with the carrier before travelling.

With the travel line selected, briefly turn Wi-Fi off and open a simple webpage. If it loads, mobile data is working through the selected setup; if it fails, return to Wi-Fi and use the no-service checks while keeping the profile installed.

If you need help, tell our Travel Desk which line is selected and the exact error in text. A cropped, redacted screenshot can wait until support asks for it.