Set your own SIM for calls and a travel profile for data, so one-time codes keep arriving and data stays prepaid.
Dual SIM is the reason travelling with an eSIM feels calm: your own number stays reachable for calls and one-time codes, while a second, cheaper line carries the data. Setting it up correctly takes one settings screen and prevents most of the surprises people blame on roaming.
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Why dual SIM changed travel
Before dual SIM, using a local plan meant removing your SIM, which meant losing your number for the duration - awkward for bank verification codes, and worse if something urgent happened at home. Dual SIM removes that trade-off. Both lines stay live; you choose which one does what.
The settings that matter
- Default voice line: your own SIM, so calls and SMS arrive as they always do.
- Default data line: the travel profile, so data is charged to the plan you already paid for.
- Data roaming: on for the travel line, off for your own line. This single setting prevents most accidental charges.
- Automatic data switching: off. Some handsets will otherwise move data to the other line when the first looks weak.
A five-minute routine when you land
- Turn the travel line on.
- Confirm the data line is the travel profile.
- Confirm roaming is on for that line only.
- Send yourself a message from your own number to confirm it still rings.
Keeping costs predictable
The rule is simple: whatever line is set as the data line is the line that pays. Voice calls and SMS are separate from data on nearly every plan, so receiving a code or answering a call does not consume your travel data allowance. If you want to be extra careful, turn off mobile data for your home line entirely for the duration of the trip.
See the full list of regions covered on our coverage page.
The dual SIM setup that works, in short
- Own SIM: calls and messages. Travel line: data.
- Roaming on for the travel line, off for your own line.
- Data switching off, so the phone cannot quietly move usage.
- Data and voice are billed separately - receiving a code costs no data.
Frequently asked questions
Will I still receive one-time codes abroad?
Yes, as long as your own line is on and receiving roaming signals. Most people keep data switched off on that line to avoid charges, while SMS still arrives.
Does answering a call use my travel data?
No. Voice and data are separate; a call is billed on whichever line took it.
Can I use two travel profiles at once?
Some phones allow two active profiles. It is rarely needed, but useful when one plan covers only part of an itinerary.
Why did my phone use data on the wrong line?
Almost always automatic data switching, or the data line reverting after a restart. Check both settings after you land.
Do I need to remove my home SIM to avoid charges?
No - switching data off for that line is enough, and you keep the number working.