Keep your home number while using a travel eSIM (dual SIM)
Most travel eSIMs are "data-only"
A large share of travel eSIMs are data-only products, so you can't make or receive local calls and texts on that eSIM number (some do include calls/texts, so check the plan type before buying). Data-based messengers and calling apps like WhatsApp, KakaoTalk, and FaceTime work normally.
How to still get verification texts on your home number
Keep your home line (a physical SIM or your existing eSIM) switched on in the phone, and route only data through the travel eSIM. Verification SMS sent to your home number (banks, messaging apps, etc.) still arrive, while data runs on the travel eSIM.
iPhone setup
Go to Settings → Cellular (Mobile Data) and assign a role to each line. Set your default voice line to your home number, and set "Cellular Data" to the travel eSIM. An iPhone uses only one line for data at a time. If you don't switch the data line, data runs on your home SIM and can incur roaming charges, so double-check this.
Galaxy (Android) setup
Go to Settings → Connections → SIM manager → Preferred SIM, and set calls and messages to your home SIM and mobile data to the eSIM. Turning off an option like "Allow switching to another SIM" prevents the phone from quietly falling back to your home SIM (and being charged) when the signal is weak.
Turn on data roaming
- Turn on data roaming for the travel eSIM line so it attaches to the local network
- Keep data roaming off on your home line to avoid charges there
- Once installed and lines are assigned, turn on the travel eSIM data after you arrive