Almost nobody chooses to stream video on a hotel wifi-less balcony. Almost everybody does it accidentally, because a phone in a pocket keeps syncing. On a plan where roaming is excluded, that habit is the difference between a trip and a bill.
What the terms actually say
The TPG Mobile SIM only plans exclude international roaming as a category. The Boost prepaid plans exclude all use overseas from the included calls and text, and the plan is only for use in Australia. The Optus prepaid data plan does not include international roaming data. None of these is a softened version of a roaming charge; they are exclusions.
Where the data actually goes
- Cloud photo and video backup running as soon as the phone sees a foreign network.
- App updates and background refresh on cellular.
- Messaging apps sending media over the mobile network rather than wifi.
- Live location and telemetry in apps that have no wifi restriction configured.
The habit that prevents it
Turn off mobile data for the trip before you leave, not when the bill arrives. Then use wifi deliberately for the things you actually want, and turn data on only where you need it and know what it costs. We cannot quote you a roaming rate for these plans because the providers do not publish one, which is another reason the default should be off rather than on.
What we could not verify. Where a provider has not published a figure we mark it unknown rather than estimate it. Re-read the provider page linked below on the day you decide.