The short answer
Use two lines. Your travel eSIM carries the data, so turn data roaming ON for the eSIM line and make it your cellular-data line. Your home SIM stays on for calls and texts, with data roaming OFF so your home carrier cannot charge you for data. Airplane mode stays off once you land. You keep your number, WhatsApp and iMessage keep working, and you only pay for the eSIM you bought.
| Setting | Travel eSIM line | Home SIM line |
|---|---|---|
| Line turned on | Yes | Yes, for calls and texts (or off to avoid all home-carrier charges) |
| Data roaming | ON | OFF |
| Cellular data line | Yes, choose this one | No |
| Allow data switching (iPhone) | Off | Off |
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iPhone settings for a travel eSIM
Label the lines
Settings → Cellular, tap each line and give it a label such as "Home" and "Travel", so you can tell them apart.
Choose the travel eSIM for data
Settings → Cellular → Cellular Data → Travel. Turn off "Allow Cellular Data Switching" so the phone never falls back to your home line for data.
Turn on data roaming for the eSIM only
Settings → Cellular → Travel → turn on Data Roaming. A travel eSIM always counts as roaming abroad; this is what lets it connect, and it does not create extra charges.
Turn off data roaming on your home line
Settings → Cellular → Home → turn off Data Roaming. Leave the line on if you want calls and texts.
Keep iMessage and FaceTime on your number
Settings → Messages → Send & Receive, and Settings → FaceTime: make sure your home number is ticked. They then run over the eSIM data.
Android settings for a travel eSIM
Open the SIM settings
Settings → Network & internet → SIMs (Samsung: Settings → Connections → SIM manager).
Make the eSIM your data SIM
Set Mobile data to the travel eSIM.
Turn on roaming for the eSIM
Tap the travel eSIM and turn on Roaming.
Turn off roaming on your home SIM
Tap your home SIM and turn Roaming off. Keep the SIM enabled for calls and texts.
Airplane mode: on for the flight, off when you land
Airplane mode turns off every mobile connection, including the eSIM, so it has to be off for the eSIM to give you data. Turn it on for the flight, and switch it off after landing; the eSIM connects to the local network within a minute or two. If you want to be extra careful about your home carrier, turn off your home line rather than using airplane mode, which would cut the eSIM too.
Will you still get texts and calls?
Yes, as long as your home line stays turned on. Receiving texts, including bank and two-factor codes, does not need data roaming. Calls and sending texts on your home line are charged at your home carrier’s roaming rates, and some carriers start a daily fee as soon as the line is used abroad, such as the AT&T International Day Pass or Verizon TravelPass. To avoid that, call and message over WhatsApp, FaceTime or iMessage instead, which use the eSIM data. Turning your home line off avoids every home-carrier charge, but you then miss calls and codes until you turn it back on.
Switching between your eSIM and your SIM
You do not need to delete or reinstall anything. Both lines stay installed, and you switch which one carries data in Cellular Data (iPhone) or SIMs (Android). When you get home, switch data back to your home line and turn the travel eSIM off or delete it once its plan has ended. Most phones with a SIM tray run one physical SIM and one eSIM at the same time; US iPhone 14 and later have no SIM tray but run two eSIMs at once.
Frequently asked questions
Do I turn off data roaming when using an eSIM?
Only on your home SIM. Turn data roaming ON for the travel eSIM, because a travel eSIM always connects as a roaming line abroad, and OFF for your home SIM so your home carrier cannot charge you for data.
Do I turn off airplane mode when using an eSIM?
Yes, once you land. Airplane mode turns off every mobile connection, including the eSIM. Leave it on during the flight and switch it off after landing.
Will I still get texts if I turn off data roaming?
Yes. Receiving texts does not use data, so your home number still gets SMS and two-factor codes with data roaming off, as long as the line itself stays turned on.
Can I use a physical SIM and an eSIM at the same time?
Yes. Most phones with a SIM tray run a physical SIM and an eSIM together, so your home SIM handles calls and texts while the eSIM handles data. US iPhone 14 and later have no SIM tray but run two eSIMs at once.
Do I turn off my primary SIM when using an eSIM?
You do not have to. Keep it on with data roaming off to receive calls and texts; turn it off only if you want to rule out every home-carrier roaming charge.
Does WhatsApp keep working with a travel eSIM?
Yes. WhatsApp is tied to your phone number, not your SIM, so it stays on your home number and simply uses the eSIM data.
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Sources & further reading
Maya Okafor
Senior Travel Connectivity Editor
Maya has tested eSIMs across 40+ countries over five years of full-time travel — from Tokyo subways to Patagonian backroads. She runs Flysimio’s hands-on network and speed testing.