If your phone is using the main SIM instead of the travel eSIM, the primary line is probably selected for Mobile Data or automatic data switching is allowing the phone to fall back to it.
Correct the line assignment before changing APN or network settings. The travel eSIM can be active without being the line that carries internet traffic.
Do not delete either SIM profile. This is normally a settings problem, and profile removal should only happen when NoveSIM Support specifically instructs you to do so.
Quick answer: Select the travel eSIM under Mobile Data, enable Data Roaming on that line, disable automatic data switching and turn off Data Roaming for the main SIM. Test with Wi-Fi disabled.
Why Is My eSIM Using My Main SIM Instead?
Dual-SIM phones manage calls, messages and data separately. A line can remain enabled for its telephone number without being used for mobile data. Review the data-only dual-SIM guide if you want to retain the main number.
Assign Mobile Data to the Travel eSIM
- Open Cellular, Mobile Network or SIM settings.
- Confirm that the travel eSIM is switched on.
- Select it as the Mobile Data line.
- Enable Data Roaming for the travel eSIM.
- Disable automatic data switching.
- Turn off Data Roaming on the main SIM.
The dual-SIM troubleshooting guide covers situations where neither line behaves as expected.
Test Which Line Carries Data
Turn Wi-Fi off, open a normal website and check the mobile-data indicator. If the travel eSIM has signal but nothing loads, use the signal-but-no-data checks.
Check APN Only If Data Still Fails
If manual NoveSIM APN entry is required, use data.esim on the travel eSIM, with username and password blank. Do not place this APN on the main carrier line.
Calls and Messages on the Main SIM
Keeping the main line active can preserve its number, but incoming calls, outgoing calls, SMS and voicemail remain subject to the home carrier’s roaming rules. Turning off its Data Roaming prevents mobile data but does not guarantee that other services are free.
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FAQ
Why did my phone switch back to the main SIM?
Automatic data switching may be enabled, or the main SIM may still be selected for Mobile Data.
Can the main SIM stay on for calls?
Yes on many dual-SIM phones, but the home carrier may charge for calls, SMS or voicemail while roaming.
Should roaming be enabled on both lines?
No. Enable it on the travel eSIM when required and keep it off on the main SIM.
Should I remove the main SIM?
Usually no. Correct the data settings first and contact Support if the phone continues using the wrong line.
Final Recommendation
When an eSIM is using the main SIM instead, assign mobile data manually before changing advanced settings.
Disable automatic switching and separate the roaming settings of the two lines.
Keep both profiles installed and send safe settings screenshots to Support if the problem continues.
