Using lots of data in Vietnam? Skip Australian roaming. Get two local eSIMs instead. They cost less than three days of Telstra roaming. They run at full speed. And they're on separate networks, so if one drops out, the other usually works.
Viettel has the best coverage in Vietnam, even in the countryside. MobiFone is a separate network. It's about as fast in the cities, and easy for tourists to sign up to. Both give you full speed and a Vietnamese number.
| Network | Coverage score (/10) |
|---|---|
| Viettel | 8.4 |
| VinaPhone | 5.3 |
| MobiFone | 4.3 |
Speeds are about equal (49.4 vs 49.3 Mbps). The difference is coverage. So Viettel is the main SIM, and MobiFone fills the gaps.
Only for new Viettel eSIMs. There may be a ₫50,000 (≈ A$3) eSIM fee. Viettel refunds it as reward points until 31 Dec 2026.
Use the buttons above. Some screens may be in Vietnamese. Google Translate's camera mode can read them.
Look for a new eSIM number (hòa mạng mới eSIM). Pick the 10GB/ngày plan, 125.000đ. Ngày means day.
Every Vietnamese SIM needs a passport photo and a face scan. Follow the prompts.
Add the eSIM to your phone. On iPhone: Settings → Mobile Service → Add eSIM.
The 30 days start straight away. Buy too early and you waste days. Buy before you leave so there's time to fix problems.
Go to a Viettel store in the city with your passport. Staff will set it up. Airport kiosks charge more. Help line (free in Vietnam): 1800 8098.
Shorter trip? FR10: 50 GB, 10 days, ₫150,000 (≈ A$8). One free eSIM per passport.
Enter your email, passport number and e-visa application number. That number is in your e-visa email.
If you wait until you land, you only get a little data. Finish within 24 hours or the eSIM is suspended.
You get a QR code on screen and by email (check spam). Scan it: Settings → Mobile Service → Add eSIM → Use QR Code.
This starts your free 10 GB for 24 hours.
Use the top-up page. Pay by card.
Major airports have MobiFone QR posters in arrivals. Scan one, photograph your passport, and verify on the spot.
Install it at home and leave it off. If both local SIMs fail, switch it on. It costs more and has no local number.
iPhone XS and newer, and most recent Samsung and Pixel phones, work. Bought it from a carrier? Ask if it's unlocked.
Phones can only use two SIMs at once. With both Vietnamese SIMs on, your Australian number is off. You'll miss its texts, like bank codes. Switch it on briefly when you need one. Need your Australian number all the time? Run it with Viettel, and turn its data roaming off.
iPhone: Settings → Mobile Service → Mobile Data → Viettel. Android: Settings → Connections → SIM manager → Mobile data.
iPhone: turn on Allow Mobile Data Switching on the same screen. Android: turn on "Switch data automatically" or "Smart data switch" in the SIM settings.
Rename them "Viettel" and "MobiFone" so you can tell them apart.
*Belong, Boost, amaysim and felix. Heavy use means buying several packs.
| Option | How it's charged | 14 days |
|---|---|---|
| Viettel + MobiFone | Local plans, full speed | ≈ A$21 |
| Optus Daily Roaming | A$5 per day for 5 GB, then another A$5 kicks in | A$70 |
| Vodafone $5 Roaming | A$5 per day; uses the data already in your plan | A$70 + plan data |
| Telstra Day Pass | A$10 per day for 2 GB, A$10 for each extra 2 GB | A$210–350 |
| Belong, Boost, amaysim, felix | Small travel packs (3–9 GB) | A$220+ |
Most slow right down after a daily limit. None guarantee Viettel. Saily slows after 5 GB a day. Jetpac slows after 3 GB. Holafly limits hotspot to 1 GB a day. Fine for maps, not for streaming.