Quick facts
| Question | Short answer |
|---|---|
| Works over data and Wi-Fi; stays on your home number | |
| Telegram | Blocking ordered on 21 May 2025 |
| eSIM phones | iPhone XS, XS Max, XR and later; many recent Android phones |
| Hotspot | Depends on the plan and the phone |
| 5G | All three networks; 26% of the population in July 2025 (ministry), 90% in early 2026 (telecoms authority) |
| Normal calls | Use a phone with VoLTE; 2G switch-off scheduled for 15 September 2026 |
| Emergency | 113 police, 114 fire, 115 ambulance, 112 disasters and rescue |
VietSim sells prepaid eSIMs for Vietnam. These answers apply whichever way you connect.
Does WhatsApp work in Vietnam?
Yes. WhatsApp sends messages and makes calls over the internet, so it works on Vietnamese mobile data and on Wi-Fi. Plans marked Data only have no Vietnamese number, so travellers on those plans call through apps such as WhatsApp or Zalo instead.
Your WhatsApp account is linked to the number you registered, not to the SIM that carries your data. It keeps working when you switch data to a Vietnamese eSIM. WhatsApp asks for a verification code only when you register again, for example after moving to a new phone. It sends the code by SMS or phone call to your number. WhatsApp’s own advice for travellers is to turn on roaming to receive it, or to check voicemail if you chose a call.
Telegram is different. On 21 May 2025 the telecoms department of the Ministry of Science and Technology ordered operators to block Telegram, with a reporting deadline of 2 June 2025. For more on messaging and ride apps, see Apps to install for Vietnam.
Will my phone work in Vietnam?
For data, your phone needs to be unlocked and to support 4G. For an eSIM, it must also be eSIM-capable. Apple lists the iPhone XS, XS Max, XR and later models. On Android, look for “eSIM” in the settings. Our eSIM setup guide covers iPhone, Samsung Galaxy and Google Pixel.
Can I use my phone as a hotspot?
A phone can share its mobile data with a laptop or a travel partner’s phone. Apple notes that Personal Hotspot needs a carrier that supports it. The number of devices that can join depends on the carrier and the iPhone model. Hotspot use also counts against your plan’s data. If you plan to share data with a group, compare the options in Pocket Wi-Fi or eSIM.
Is there 5G in Vietnam?
Yes. Viettel launched 5G on 15 October 2024, VinaPhone on 20 December 2024 and MobiFone on 26 March 2025. The two official figures differ by date: the Ministry of Science and Technology reported 4G at 99.8% and 5G at 26% of the population in July 2025, and the Vietnam Telecommunications Authority reported more than 40,000 5G base stations covering 90% of the population in early 2026. Your phone joins 5G only if the phone, the plan and the location all support it. Otherwise it uses 4G. The networks are compared in Viettel, VinaPhone or MobiFone.
Can I make normal phone calls?
On a Vietnamese line that includes calls, yes, but check VoLTE (calls over 4G). Under QCVN 117:2023/BTTTT, 4G phones made or imported for the Vietnamese market must support VoLTE from 1 July 2024. A phone you bring with you is not covered by that rule. Phones without it fall back to older networks for calls. Vietnam scheduled its 2G switch-off for 15 September 2026 and plans to close 3G by 2028. If your phone is several years old, check its specifications for VoLTE.
Calls to your home number while you are in Vietnam are handled and charged by your home carrier.
What if my eSIM does not connect?
Turn on the line, select it for mobile data and allow data roaming on that line if needed. The full steps are in Turn on your eSIM in Vietnam and eSIM not connecting.
Emergency numbers
- 113 police
- 114 fire and rescue
- 115 ambulance
- 112 disasters, incidents and requests for help, free of charge nationwide
The UK government’s travel advice notes that these lines are operated in Vietnamese only. Keep your hotel’s address written down, and ask a local person to call for you if you can.