What the +84 code actually is
+84 is the international dialling prefix assigned to Vietnam. It replaces the leading 0 you see on every Vietnamese phone number written inside the country. That single substitution is the whole trick: a Hanoi mobile printed as 0912 345 678 becomes +84 912 345 678 when dialled from abroad.
Vietnam's numbering plan is managed domestically, and the +84 prefix is what the rest of the world uses to reach it. If you are dialling from a landline in some countries you may need the international access code (00 in the UK and much of Europe, 011 in the US and Canada) before the 84, but from a mobile the + symbol works everywhere.
How to dial a Vietnamese number from abroad
| You want to reach | Written locally | Dialled from abroad |
|---|---|---|
| A mobile in Hanoi | 0912 345 678 | +84 912 345 678 |
| A mobile in Ho Chi Minh City | 090 123 4567 | +84 90 123 4567 |
| A landline in Hanoi | (024) 3825 xxxx | +84 24 3825 xxxx |
| A landline in Da Nang | (0236) 382 xxxx | +84 236 382 xxxx |
Two rules cover almost every case:
- Drop the leading 0 from the local number.
- Keep everything else exactly as written.
Mobile numbers in Vietnam are ten digits locally, so the international form is +84 followed by nine digits. Landline area codes are two or three digits after the 0, and the subscriber number follows.
How to call home from Vietnam
From a Vietnamese phone, dial + followed by the country code of the place you are calling, then the number without its own leading 0. For the UK that is +44, for the US and Canada +1, for Australia +61, for India +91.
If you are on a Vietnamese SIM or eSIM with a voice allowance, the international rate depends on the plan, not on the +84 code. Most travellers find it cheaper to use a messaging app over data than to place a traditional international call. Our guide to international minutes plans for Vietnam explains when a voice allowance is worth paying for and when it is not.
Do you actually need to dial +84 on your trip?
Rarely. Almost every call a visitor makes in Vietnam is either to a local business, a Grab driver or a hotel, and those numbers are dialled in local format from a Vietnamese phone. The +84 code matters in three situations:
- Someone abroad is trying to reach your Vietnamese number.
- You are filling in a form that asks for your number in international format.
- You are calling Vietnam from your home country before you travel, for example to confirm a booking.
For everything else, a data connection does the work. Grab, Zalo, WhatsApp and Google Maps all run over data, and none of them care about the +84 prefix.
The practical setup for a Vietnam trip
A data eSIM installed before you fly means you land connected: no queue at the airport counter, no need to hand over your passport for a local SIM, and no roaming bill from your home operator. You keep your usual number active for incoming SMS while the eSIM handles data.
If you use an iPhone, the dual-SIM behaviour is worth understanding before you travel; our Vietnam eSIM for iPhone guide covers how to keep WhatsApp on your home number while data runs on the eSIM. Android users have a slightly different setup path, covered in Vietnam eSIM for Android.
If you plan to tether a laptop or share data with a travel companion, check the rules first: Vietnam eSIM as a hotspot explains what tethering does to your data allowance.
When a local SIM still makes sense
A local SIM gives you a Vietnamese phone number, which is useful if you need to receive calls from Vietnamese businesses, register for a service that requires a local number, or stay for several weeks. The trade-off is the airport queue, the passport registration and the fact that your home number goes offline.
For a one- or two-week trip, the eSIM is the simpler answer. For longer stays, or if you specifically need a Vietnamese number, a local SIM is worth the extra step. Our Vietnam phone and internet FAQ covers the number question in more detail.
Common mistakes with the +84 code
- Keeping the leading 0. +84 0912... will not connect. Drop the 0.
- Using 84 without the +. Some networks will treat a bare 84 as a local number. Always use +84.
- Confusing the country code with the area code. Hanoi's area code is 24, not 84. The 84 is the country.
- Assuming +84 means you need a Vietnamese SIM. It does not. It is just the dialling prefix.
What to buy
If your trip is about staying connected rather than making international calls, buy a Vietnam eSIM before you fly. The Vietnam eSIM store lists the current plans with data allowances, validity periods and prices in USD, and installation takes a couple of minutes over your home Wi-Fi. If you run into trouble on landing, the help centre has step-by-step activation and troubleshooting guides.