How to Turn Off Domestic SIM Data Roaming

Why turn off data roaming on home SIM?

Abroad, if you use eSIM for data but data roaming is ON for your home SIM, the system can use the home line for data and you’ll get high roaming charges. So use eSIM only for data and keep data roaming OFF on your home SIM.

iPhone: Turn off “Data roaming” for home SIM (recommended setup)

1. Open Settings.
2. Tap Cellular (or Mobile Data).
3. In Cellular plans, select your home carrier (main number).
4. Turn Data roaming OFF.
5. Go back and set Cellular data to eSIM (travel).
6. Set Allow Cellular Data Switching to OFF if possible.
7. Keep Default voice on home USIM so you still get calls and SMS.

Samsung Galaxy: Turn off (One UI)

1. Open Settings.
2. Go to Connections > SIM manager (or Mobile network).
3. Set Mobile data line to travel eSIM.
4. For home USIM (main), turn Data roaming / International data OFF.
5. For travel eSIM, turn Data roaming ON if needed.

Quick check after setup

Turn airplane mode off, then test a simple page in the browser. If data doesn’t work, follow the checklist at /guide/esim-data-not-working-abroad.