First time using an eSIM and worried about your Taiwan number? This guide covers whether you can keep your Taiwan line, receive bank OTP / verification SMS abroad, dual-SIM requirements, and what to do if your phone is not dual-SIM standby (DSDS).

Many first-time eSIM users worry less about installation and more about: “Will my Taiwan number disappear?”, “Can I still get bank OTPs abroad?”, and “Does an eSIM replace my physical SIM?”

If your phone supports eSIM and dual-SIM dual-standby (DSDS), you can usually keep your Taiwan number for calls and SMS while using a travel eSIM for data. If your device is not DSDS-ready—or settings are wrong—OTP delivery can fail.

Can an eSIM keep your Taiwan number?

Yes. With eSIM + DSDS, your travel eSIM handles overseas mobile data while your Taiwan number stays active for calls, SMS, and bank OTPs. You do not need to cancel or replace your home line.

You still need three conditions:

  • Your phone supports eSIM
  • Your phone supports dual-SIM dual-standby (DSDS)
  • Travel eSIM is installed and set for mobile data, while the Taiwan line stays enabled

Does an eSIM replace your physical SIM?

No. An eSIM adds a digital line inside the phone. With DSDS, travel data and your Taiwan number can run side by side with different jobs.

Typical travel setup: travel eSIM = mobile data; Taiwan SIM/eSIM = voice + SMS (including OTPs).

Can you receive bank OTP SMS abroad?

Usually yes—if the Taiwan line stays registered on the network and is not disabled. Keep the Taiwan line enabled for SMS even when the travel eSIM is your data line. If OTPs fail, check airplane mode, dual-SIM settings, and whether the carrier blocked SMS roaming.

No DSDS? Workarounds

  • Use Wi‑Fi calling / messaging apps where possible
  • Carry a second device for the Taiwan SIM
  • Ask your bank about app-based OTP alternatives before you fly

Confirm eSIM + DSDS support for your exact model before departure, then install the travel eSIM early and test dual-line settings at home.