How to Use Dual SIM in Vietnam: Keep Your Home Number for Bank OTPs While Using an eSIM for Unlimited Data
Quick Answer: Yes, modern smartphones (iPhone XS and newer, Samsung Galaxy S20 and newer, Google Pixel 3 and newer) allow you to use Dual SIM simultaneously in Vietnam. Keep your primary physical home SIM active on standby to receive bank OTP codes, two-factor authentication (2FA) SMS, and emergency calls with zero roaming fees for incoming texts. Set your secondary Kovitel Viettel 5G eSIM as the dedicated Cellular Data line for 5GB/day ultra-fast internet.
Why Travelers Need Dual SIM Active in Vietnam
International travel in 2026 relies heavily on digital authentication. When booking trains on 12Go, reserving domestic flights on Vietnam Airlines, or paying for hotels, your banking app will trigger a 3D-Secure One-Time Password (OTP) via SMS to your registered domestic telephone number. If you remove your home physical SIM and swap in a local plastic card, you risk being completely locked out of your financial accounts.