Best eSIM for Vietnam

The first thing you do on a Hanoi pavement is point your phone at a menu. Vietnam is a country you read through a translation app: street-food signs, the bus timetable in Hue, the price board at a Hoi An tailor, and the Grab or Xanh SM booking that replaces bargaining with a taxi driver. It is also a country where you cross six lanes of scooters by trusting a blue dot on Google Maps. None of that works on airport Wi-Fi once you have left the airport.

Local SIMs from Viettel, Vinaphone and MobiFone are sold at the arrivals counters at Tan Son Nhat (SGN) and Noi Bai (HAN), but Vietnam has tightened SIM registration in recent years and every one must be tied to a passport at purchase. An eSIM for Vietnam is set up before you fly, connects when your phone first sees a Vietnamese network in the terminal, and keeps your home SIM in place for calls and OTPs with roaming data switched off. From the taxi rank onwards, the menus translate themselves.

Vietnam is a long, thin country that most visitors cross end to end: Hanoi and Ha Long Bay, then Hue, Da Nang and Hoi An, then Ho Chi Minh City and the Mekong Delta, over two to three weeks. Buy validity for the entire route with a margin, then data for a heavy user, because translation, maps, Grab and photo uploads run all day (see the plans above); a top-up queues behind the first plan.

5G only launched commercially in Vietnam in late 2024, so it is concentrated in Hanoi, Ho Chi Minh City, Da Nang and the provincial capitals, and 4G is what carries you along the coast and up into the highlands. A 5G phone on the eSIM uses it where it exists and drops back automatically. Hotspot is useful on overnight trains; check the plan card.

You do not need a Vietnamese number. Grab, Xanh SM and Be accept your existing number, hotels and tour desks message on WhatsApp or Zalo, and the MoMo and VNPay QR payments locals use need a Vietnamese bank account whichever SIM you hold. If Vietnam is one leg of a loop through Cambodia, Thailand or Laos, compare a Southeast Asia bundle; for Vietnam alone the single-country plan is better value. A Siem Reap side trip needs a Cambodia plan. Check your handset on the device page before you buy.

Vietnam's networks are Viettel, Vinaphone and MobiFone, with Viettel the largest and the one that reaches furthest into the countryside. 4G covers the cities, the coastal Highway 1 corridor and most district towns, and 5G, commercial only since late 2024, is limited to Hanoi, Ho Chi Minh City, Da Nang and the bigger provincial cities. The plan card shows the partner network your eSIM uses; the phone chooses the strongest signal itself.

Gaps follow the landscape. An overnight Ha Long Bay cruise loses signal among the limestone islands, the Ha Giang loop and the trekking valleys around Sapa drop out for hours, Phong Nha's caves have nothing inside, and the Mekong Delta is fine in the towns but thin on the waterways. Phu Quoc is well covered along the developed west coast and patchy in the north. In the cities, coverage is dense right down to the alleyways.

• Ho Chi Minh City: dense 4G with 5G across District 1 and the central districts.
• Hanoi: strong throughout the Old Quarter, West Lake and out to Noi Bai.
• Da Nang: good along My Khe beach and in the city, 5G in the centre.
• Hoi An and Hue: reliable 4G in the old towns.
• Nha Trang and Phu Quoc: solid on the beaches and resort strips.
• Sapa and Ha Giang: fine in town, unreliable on the trekking routes.
• Ha Long Bay: signal near Ha Long city, patchy once the boat is among the islands.

For the classic two-to-three-week route the eSIM is the practical choice: nothing to register, data from the terminal, one price. A local SIM suits people staying for months who want a Vietnamese number for Zalo and local wallets. Home-carrier roaming is worth considering only for a very short visit of a night or two.

1. Choose a Vietnam plan above and pay; the eSIM arrives by email within minutes.
2. iPhone on iOS 17.4 or later: tap the direct install link in the email. Older iPhones: Settings, then Mobile Data, then Add eSIM, and scan the QR code.
3. Android: Settings, then Connections or Network, then SIM manager, then Add eSIM; scan the QR code or type the SM-DP+ code.
4. Label the line Vietnam data.
5. Turn on Data Roaming for the eSIM line and switch mobile data off on your home SIM, which stays in the phone for calls and OTPs.
6. On landing at Tan Son Nhat, Noi Bai or Da Nang, select the eSIM as your data line; it connects in the terminal, so Grab is ready by the time you reach the arrivals kerb.
7. Validity starts at that first connection, not at purchase or install.

Install the Vietnam eSIM on home Wi-Fi a few days before departure and leave it inactive; it cannot start its clock until it has connected to a Vietnamese network. Keep your home SIM as the data line for the flight and for any connection in Bangkok, Singapore or Kuala Lumpur, since the plan is for Vietnam only. Many arrivals at Tan Son Nhat land late in the evening, when the taxi touts are busiest, so an eSIM that is already installed lets you open Grab before you leave the terminal. Switch it on when you land, not before.