Vietnam Phone Numbers: Format, Prefixes, and How to Call

Understanding Vietnamese phone numbers

Vietnamese phone numbers have a simple structure, but there's one rule that trips up almost everyone: when you add the international dialing code, you drop the leading zero.

A typical Vietnamese mobile number looks like this: 098 1234 5678. That leading zero is only used for domestic calls. As soon as you're calling from abroad, you replace the 0 with +84 (Vietnam (베트남 / 越南 / ベトナム)'s country code), giving you +84 98 1234 5678.

For landlines, the same principle applies. A Hanoi number might be 024 3xxx xxxx domestically, or +84 24 3xxx xxxx internationally. The zero vanishes; the country code arrives.

All Vietnamese mobile numbers are 10 digits long (including the leading zero). Landlines are 10 or 11 digits depending on the province. If someone hands you a number that's shorter or longer than that, double-check — they may have added or dropped a digit by mistake. This is especially common when a restaurant scribbles a reservation number on a receipt or when a taxi driver rattles off digits quickly in Vietnamese.

Recognizing mobile carriers by prefix

Mobile numbers in Vietnam start with specific prefixes that indicate which carrier owns the line. This matters if you're buying a local SIM or saving contacts.

Viettel (state-owned, largest coverage): 032, 033, 034, 035, 036, 037, 038, 039, 086, 096, 097, 098

Mobi (MobiFone) (state-owned): 070, 076, 077, 078, 079, 089, 090, 093

Vinaphone (state-owned): 081, 082, 083, 084, 085, 088, 091, 094

Vietnamobile (newer, smaller): 052, 056, 058, 092

Why does the carrier matter? If you're traveling to remote areas — say, the mountain roads of Ha Giang or the valleys around Sapa — Viettel's network is noticeably stronger. In cities like Saigon, Da Nang, or Hanoi, all three major carriers perform about the same. Vietnamobile is the budget option with decent urban coverage but weaker signal once you leave main highways.

Landlines vary by region. Numbers in Hanoi (하노이 / 河内 / ハノイ) start with 024, Saigon with 028, Hue with 0234, Da Nang with 0236. But for most travelers and expats, you'll deal almost exclusively with mobile numbers.

Calling locally (within Vietnam)

If you have a Vietnamese SIM, calling another Vietnamese number is straightforward. Keep the leading zero. Dial the full number as written: 098 1234 5678, or 024 3xxx xxxx for a landline.

Text messages work the same way — use the zero.

A few numbers worth memorizing or saving: 113 for police, 114 for fire, 115 for ambulance. These are free from any phone, including payphones and phones without a SIM. In practice, getting a Vietnamese speaker to help you make the call is more effective — dispatchers rarely speak English outside Hanoi and Saigon.

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Calling Vietnam from abroad

Drop the zero, add +84. So 098 1234 5678 becomes +84 98 1234 5678. You can dial this on WhatsApp, Viber, or any calling app that accepts international numbers. If you're calling from a phone with a traditional carrier, you may dial +84 98 1234 5678 or, in some countries, 011 84 98 1234 5678 (depending on your carrier's format).

For callers from common origin countries: from the US or Canada, dial 011 84 then the number without the zero. From the UK, dial 00 84. From Australia, dial 0011 84. From Japan or South Korea, dial 010 84. Most modern smartphones let you just use the + symbol and skip memorizing exit codes altogether.

Saving contacts the right way

If you're planning to stay in Vietnam or visit frequently, save numbers in full international format (+84 98 1234 5678). That way, when you travel back home, the number still works. You won't accidentally try to dial a zero-prefixed Vietnamese number from abroad and watch the call fail.

Many Vietnamese will give you their number with the leading zero — that's normal. Just mentally translate it: drop the zero, add +84.

A practical habit: when you book a homestay in Ninh Binh, reserve a table at a bun cha spot in Hanoi, or arrange a motorbike rental in Da Lat, save the contact immediately in +84 format. Your future self, trying to call from a different country or on a different SIM, will thank you.

Getting a local SIM

You can buy a prepaid SIM at the airport, any carrier shop (Viettel, Mobi, Vinaphone have stores in every city), or convenience stores like Circle K and GS25. Viettel tends to have the best rural coverage — important if your trip includes places like Ha Giang, the Central Highlands, or Phu Quoc island's less-developed north end. All three major carriers charge similar rates: around 50,000–100,000 VND ($2–4 USD) for a starter pack, which includes a number and some credit.

Activation takes a few minutes. You'll need to show your passport. Within an hour, you're calling and texting.

For data-heavy plans (which most travelers want), look for tourist SIM packages that bundle 1–2 GB per day for 15 or 30 days. A 30-day package with daily data runs about 150,000–200,000 VND (roughly $6–8 USD). At Tan Son Nhat airport in Saigon or Noi Bai airport in Hanoi, carrier booths are right outside the arrivals hall — prices are marginally higher than in-town shops, but the convenience is worth it if you want data working before you hit the taxi queue.

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Calling internationally from a Vietnamese number

To call abroad from Vietnam, dial +your-country-code (or the international prefix 00 + country code) and the number. A call to the US would be +1 followed by the area code and number. Rates on prepaid plans are typically 3,000–5,000 VND ($0.12–0.20 USD) per minute for calls to the US, Europe, or Australia, depending on the carrier and plan. Data is usually cheaper and more efficient — use WhatsApp, Viber, Messenger, or FaceTime over WiFi or mobile data instead.

"Zalo" and the apps that actually matter in Vietnam

You'll hear about "Zalo" within your first 48 hours in the country. It's Vietnam's dominant messaging app — think of it as the local WhatsApp. Hotels, tour operators, landlords, and restaurants all use it. When a "banh mi" stall owner in Hoi An or a "ca phe" shop in Saigon gives you a number, there's a good chance they expect you to reach them on Zalo rather than through a regular call.

Download Zalo before you arrive and register with your Vietnamese number once you have a SIM. The interface is available in English. You can send messages, make voice and video calls, and even transfer small amounts of money through it. For day-to-day communication — booking a street food tour, confirming a pickup time, asking a guesthouse about luggage storage — Zalo is faster and more reliable than calling.

WhatsApp and Messenger still work fine for talking to other foreigners and for businesses that cater to tourists. Viber has a small but loyal user base, especially among the older generation. But if you only install one local app, make it Zalo.

Common confusion points

Zero or no zero? Domestic: keep it. International: drop it.

Can I use my home phone number? If your carrier offers international roaming, yes, but it's expensive. A local SIM is almost always cheaper and simpler.

Do I need WhatsApp or Messenger? Not required, but recommended for voice and video calls. Many Vietnamese use Viber or Zalo (a local messaging app) as well. WiFi calling through any of these apps avoids carrier charges entirely.

What if I dial a wrong number? You'll get a recorded message (in Vietnamese) saying the number doesn't exist or is unavailable. No charge usually applies for incomplete or failed calls on prepaid SIMs.

Can I keep my Vietnamese number after leaving? Prepaid SIMs expire if you don't top up credit within a set window — usually 60–90 days of inactivity. If you plan to return, add 50,000 VND of credit before you fly out. That extends the number's life. Losing a number means losing your Zalo account linked to it, which can be annoying if you've built contacts on it.

What surprises foreigners about Vietnamese phone numbers

Everyone texts before calling. Cold-calling is considered slightly abrupt. Most Vietnamese will send a Zalo or SMS message first, even for urgent things. Follow their lead — a quick "Xin chao, toi muon dat ban" ("Hello, I'd like to book a table") over Zalo goes further than a phone call where neither side speaks the other's language well.

Spam calls are common. If you get a local SIM, expect occasional calls from insurance companies, real estate agents, and automated messages — sometimes within hours of activation. Don't panic; just decline. You can block numbers through your phone's settings or through Zalo's built-in spam filter.

Phone numbers double as identity. Your Vietnamese phone number is tied to your passport during SIM registration. It's also used as your login for Zalo, some banking apps, and e-wallet services like MoMo (useful for paying at Ben Thanh Market or grabbing a "bia hoi" at a street corner). Treat it like a semi-official ID while you're in the country.

Businesses change numbers. Small restaurants, guesthouses, and tour operators in Vietnam sometimes switch phone numbers when they change SIM plans or carriers. A number you saved six months ago for a great "pho" place near the Temple of Literature might be dead on your next visit. Always cross-check with Google Maps or the business's Zalo page before calling.

Quick reference

• Country code: +84
• Mobile number length: 10 digits (with leading zero)
• Domestic call format: 0XX XXXX XXXX
• International call format: +84 XX XXXX XXXX
• Emergency numbers: 113 (police), 114 (fire), 115 (ambulance)
• Major carriers: Viettel, MobiFone, Vinaphone, Vietnamobile
• SIM cost at airport: 50,000–200,000 VND depending on data package
• SIM activation requirement: passport
• Primary messaging app: Zalo (download before arrival)
• Best carrier for rural travel: Viettel
• International call rate (prepaid): ~3,000–5,000 VND/minute
• SIM inactivity expiry: typically 60–90 days without top-up

Frequently Asked Questions

How do I dial a Vietnamese mobile number from abroad?

Drop the leading zero and add +84, Vietnam's country code. So 098 1234 5678 becomes +84 98 1234 5678. From the US or Canada dial 011 84 then the number without the zero; from the UK dial 00 84; from Australia dial 0011 84; from Japan or South Korea dial 010 84. WhatsApp and Viber accept the +84 format directly.

What mobile carrier should I buy a SIM from in Vietnam?

Viettel is the largest carrier and has the strongest coverage in remote areas like Ha Giang and Sapa. MobiFone and Vinaphone perform comparably to Viettel in cities like Hanoi, Saigon, and Da Nang. Vietnamobile is the budget option with acceptable urban coverage but noticeably weaker signal outside main highways.

When calling within Vietnam, do I keep or drop the leading zero?

Keep the leading zero for all domestic calls. Dial the full 10-digit number as written, for example 098 1234 5678 for mobile or 024 3xxx xxxx for a Hanoi landline. The zero is only dropped when dialing from outside Vietnam. The same rule applies to text messages sent from a Vietnamese SIM.

Practical notes

Save important numbers (hotels, restaurants, friends) in international format from day one. Buy a local SIM if you're staying more than a few days — it costs almost nothing and solves the calling problem. If you only need data and messaging, WiFi at your accommodation often suffices, though mobile data (4G) is cheap and reliable in cities. 5G is rolling out in Hanoi, Saigon, and Da Nang, though coverage is still patchy outside central districts.

One more thing: if you're arranging transport — a car to the Cu Chi Tunnels from Saigon, a driver for the Ha Giang loop, a boat in Ninh Binh — confirming by phone call (or Zalo voice message) the evening before is standard practice. A text saying "Ngay mai, 8 gio sang" ("Tomorrow, 8 AM") removes any ambiguity and shows you're serious about the booking.

Final note

Vietnamese phone numbers follow a clean, predictable system once you internalize the one core rule: zero for domestic, +84 for everything else. Get a local SIM on arrival, save contacts in international format, and install Zalo. After that, calling and messaging in Vietnam works just as smoothly as anywhere — and costs a fraction of what you'd pay on roaming.