Guide section · updated August 2026

Staying online in Vietnam — SIM, eSIM and Wi-Fi

Viettel SIM from 100K ₫, eSIM (Airalo, Holafly), WiFi and VPN. Three carriers, plans and roaming. Updated 2026.

eSIM before you fly, or a SIM on arrival

The whole section comes down to this one choice, and it is not about money: the difference is about four dollars. It is about whether you end up with a Vietnamese phone number.

eSIM compared with a physical SIM
What we compareeSIM in advanceSIM on arrival
Online the moment you landYes — activated before you flyAfter 15–40 minutes in the queue
Passport neededNoYes, always
A Vietnamese numberNoYes
Grab, delivery, a local bankCannot sign up — they need a local numberWorks
Cost for 30 days$11–19100–200k ₫ — that is $4–8
Phone requirementsiPhone XS and newer, Samsung S20+, Pixel 3+Any phone

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The short answer. Two weeks or less, a phone made after 2018 and no local services — take an eSIM: you are online while the plane is still taxiing. Staying longer, ordering Grab and food, or opening a local account — you need a physical SIM: every one of those asks for a Vietnamese number, and there is no other way to get one. The arrangement that works most often is both: an eSIM for day one, a local SIM the day after.

A SIM on arrival

Carrier desks run around the clock in the arrivals hall; the same plan in a city store costs 10–20% less. Your passport is required: since 2018 every number is registered to a document, and an unregistered SIM gets cut off. Buying one step by step is in the SIM card guide.

Three carriers

  • Viettel · ~54% of the market · hotline 198Best in the country: mountains, islands, villages. Travelling the whole country111 Mbps
  • Vinaphone · ~23% of the market · hotline 18001091Excellent in cities and resorts. Resorts, 10–15% cheaper73 Mbps
  • Mobifone · ~19% of the market · hotline 9090Good in cities and along the coast. Budget, 10–20% cheaper55 Mbps

The plans they will offer at the desk

Prepaid SIM plans
CarrierPlanDataValidPrice
ViettelST30K3 GB a day15 days150k ₫
ViettelST90K6 GB a day30 days200k ₫
VinaphoneD60G4 GB a day30 days180k ₫
MobifoneF200N4 GB a day30 days160k ₫

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Topping up

  • A scratch card from Circle K or FamilyMart — the code goes in via *100*code#
  • The carrier’s own app: My Viettel, My VNPT, My MobiFone
  • Check the balance with *101#, remaining data with *102#

eSIM providers

The profile installs in five minutes at home, so you have data the moment you land. It costs two to three times a physical SIM for less data — what you are buying is the absence of a queue and a passport check.

eSIM providers for Vietnam
ProviderPlanPriceRuns on
Airalo10 GB / 30 days$16Viettel
HolaflyUnlimited / 7 days$19Vinaphone
Yesim5 GB / 14 days$12Viettel
Saily5 GB / 30 days~$13Viettel

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Wi-Fi, and whether you need a VPN

Free Wi-Fi is nearly everywhere: hotels, cafés, restaurants, airports. Between six and ten in the evening it sags everywhere except coworking spaces. Speeds city by city are in internet in Vietnam.

  • Coworking spacesDedicated line, $3–5 a day50–150 Mbps
  • 4–5★ hotelsSteady in the evening too30–100 Mbps
  • Chain cafésHighlands, Coffee House20–50 Mbps
  • 2–3★ hotelsSags after six10–30 Mbps

On VPNs — no scare stories, no promises. Telegram has never been officially unblocked. Providers were ordered to cut access in May 2025; in July it came back for most people — with no announcement and unevenly, sooner on some networks than others, and some users stayed blocked. There is no guarantee it will open on your carrier. Instagram works, Facebook works most of the time but gets throttled during sensitive periods. The practical conclusion is one line: install a VPN before you fly. Inside the country several of those apps are already missing from the local stores, and you will have nothing to download them with. Using a VPN as an ordinary traveller is not enforced against anyone — millions of Vietnamese live that way.

  • ExpressVPN~$8 a month. Steadiest on Vietnamese networks
  • NordVPN~$4 a month. The Saily eSIM comes with the plan
  • Surfshark~$3 a month. Cheapest, unlimited devices

An open network does not encrypt anything. Use mobile data or that VPN for banking, not the café Wi-Fi. And budget the data: maps, navigation and messaging together burn 2–3 GB a day.

Roaming on your home plan

Leaving roaming on is the most expensive mistake of the first hour: background updates can burn a day pass before you clear the terminal. Turn mobile data off on the home SIM before you board and keep it only for bank codes.

Home-carrier roaming compared with a local SIM
CarrierPer dayDataPer monthVersus a local SIM
US — T-Mobile, AT&T, Verizon~$10–12 a day0.5–5 GB~$300–36030–40× a local SIM
UK and EU carriers~$6–10 a dayvaries~$180–30020–30× a local SIM
Australia — Telstra, Optus~$5–10 a dayvaries~$150–30015–30× a local SIM

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Short answers

Viettel has the best coverage (mountains, islands). The ST90K plan gives 6 GB/day for 30 days at ~200,000 ₫. Buy at the airport (24/7 counters) or an official store with your passport — an unregistered SIM can be blocked.

Yes, and you don’t need a VPN. There was a block: carriers cut access from 26 May to 9 July 2025 on orders from the Department of Telecommunications. Access came back on its own and has held since. A VPN is still handy for Facebook and Instagram, which run slowly.

Yes for convenience — activate it 5 minutes before landing. Airalo offers 10 GB/30 days for about $16; Holafly and Yesim are alternatives. The downside: no local number (you can’t register for Grab), and it costs more than a local SIM.

Much more than a local SIM — home-carrier day passes are often $10–12/day. Keep your home SIM for 2FA and bank texts, and use a Vietnamese SIM or eSIM for data.

If you need more depth

The carriers themselves, a speed check for when you are there, and the reads that go deeper.