How dual SIM works
Your phone can store more than one mobile line and, on compatible models, keep two lines active at once. You usually choose a default line for calls and texts and a separate line for mobile data.
A common travel setup
Keep your normal SIM enabled for incoming calls or messages, set the travel eSIM as the mobile-data line, and disable data roaming on the home SIM. This preserves access to your normal number while the travel plan handles internet access.
Watch for incoming-call charges
Receiving calls or SMS on your home line can still be subject to your carrier rules. Keeping the line active does not make international voice roaming free.
Not every phone behaves the same
The number of active SIMs, whether two eSIMs can be active together, and how calls are routed depend on the phone model and carrier restrictions. Check the device documentation before relying on a specific setup.
Label the lines in your phone settings—such as “Home” and “Travel”—so it is obvious which one is selected for mobile data.