Vietnam eSIM with phone number: OTP & Grab calls guide

Many travelers discover the hard way that a data-only eSIM is not enough for essential tasks in Vietnam. Services like Grab, local banking apps, and food delivery platforms often send a one-time password (OTP) via SMS to verify your account or transaction. Without a real Vietnamese phone number, that OTP never arrives, and you cannot complete the verification.

Data-only eSIMs from global brands (Airalo, Holafly) and even some local eSIMs (like Viettel data-only plans) assign no phone number – they only provide internet access. If a Grab driver needs to call you to confirm the pickup spot, they cannot reach you; the app only shows a non-functional placeholder. Similarly, many Vietnamese bank apps and e-wallets (Momo, ZaloPay) require an SMS OTP for every transaction. With a Vinaphone eSIM that includes a real 10-digit Vietnamese number, these problems disappear.

Only Vinaphone eSIM plans issued directly by Vinaphone come with a real Vietnamese phone number. The Vinaphone eSIMs we offer (10-day, 15-day, 30-day) each assign a standard 10-digit mobile number (prefix 09x or 08x) upon activation. This number can receive incoming calls and SMS from any Vietnamese or international number.

In contrast, the Viettel eSIMs we sell are data-only – no local number is assigned. Mobifone eSIMs (resold via Skyfi) are also data-only. Global eSIM providers like Airalo and Holafly offer only internet access for Vietnam; they do not include any voice or SMS capability. So if receiving OTPs or calls matters, the Vinaphone plans are the only option. Note that even after your data allowance is used up, the Vinaphone number continues to receive calls and texts for a while – though we recommend topping up data for continuous connectivity.

After you activate the Vinaphone eSIM, a 10-digit Vietnamese number is automatically assigned (you do not choose it). This number can receive incoming calls from any domestic or international number – the call is a standard mobile call, not VoIP. Outbound calls and sending SMS are not included in the data plan; to make calls or send texts, you must top up credit via Vinaphone’s own system (an add-on we do not sell).

Receiving SMS, including OTP messages from banks, Grab, ShopeeFood, Momo, and other services, is free and works as long as the phone is on and connected to a network. For best results, use the Vinaphone eSIM in dual-SIM mode: keep your home SIM for calls and texts to your home country, and use the Vinaphone eSIM for data plus incoming communications in Vietnam.

To get the most out of your Vinaphone eSIM, run it alongside your home SIM. Install the Vinaphone eSIM as your data line and keep your home SIM for voice and SMS from home. On iPhone: go to Settings > Cellular, set Vinaphone for 'Cellular Data' and your home SIM for 'Default Voice Line' (or choose per call). On Android: assign Vinaphone for mobile data, set home SIM for calls/SMS, and enable 'Ask every time' for outgoing calls if you want flexibility.

To ensure OTPs from Vietnamese services arrive reliably, keep both SIMs active, disable airplane mode, and enable data roaming for the Vinaphone eSIM. If your home SIM is not needed for data, turn off its data roaming to save battery. This dual-SIM setup gives you the best of both worlds: your home number remains reachable, and you have a working local number for Vietnam.

Purchase a Vinaphone eSIM from us (choose the 10, 15, or 30-day plan). After payment, you will receive a QR code by email within 60 seconds. Scan the QR code on your phone: on iPhone go to Settings > Cellular > Add eSIM; on Android go to Settings > Network & Internet > Add eSIM. Label the eSIM as 'Vinaphone' and set the APN to 'vinaphone' (usually auto-filled, but double-check).

Upon arrival in Vietnam, enable data roaming for this eSIM. To test that the number works, ask a friend to call your Vinaphone number – you should hear it ring. If you have no service after a few minutes, reboot your phone and verify the APN. Important: If you are using a mainland China iPhone 14 (or later China model), those devices lack eSIM hardware – you will need a physical SIM instead. For everyone else, eSIM setup is straightforward.

If OTP messages are not arriving, first ensure that the Vinaphone eSIM is selected for mobile data and that data roaming is ON. Some services send OTP only to the number registered – make sure you entered your Vinaphone number (not your home number) during account setup. For Grab, update your phone number in the app's account settings to the Vinaphone number; drivers will then call or SMS that number.

For banking apps, register or update your phone number before your trip if possible. If OTPs still fail, try forcing the network to 3G or 4G on the Vinaphone line (some OTP services work better on older network generations). Also verify the APN is exactly 'vinaphone' (lowercase) – a wrong APN can block both data and SMS. Restart the phone after any APN change.