A foreigner can buy a Vietnamese SIM only with an original passport, and since spring 2026 the operator also verifies your face. A month with 3 to 6 GB a day costs about $6 to $8 (150,000 to 200,000 VND). Three things matter for a long stay: the operator, the verification and keeping your home number.
How do you buy a SIM card in Vietnam as a long-stay foreigner?
Take your original passport to an operator desk in the arrivals hall at Noi Bai, Tan Son Nhat or Da Nang, or to a branded Viettel, Vinaphone or MobiFone shop in town. The staff scan the passport, take a portrait photo and activate the number.
- Bring the original passport, because photocopies and phone photos are refused.
- Ask for the plan length before paying, since some cheap packs last only 15 days.
- Let the clerk take your portrait photo for the face check.
- Confirm the number the same day in the operator app: My Viettel, My VNPT or MyMobiFone.
- Top up once a month so the number stays active.
What does the 2026 face verification check?
The operator verifies four fields: identification number, full name, date of birth and your face. The rules come from Circular 08/2026/TT-BKHCN of the Ministry of Science and Technology and apply from spring 2026. The photo is taken on the spot, so the passport holder has to be present at the desk.
Foreigners are checked either electronically against the national entry and exit database or in person at an operator point. For a second and later SIM on the same passport, the operator may text a code to your earlier registered number or ask for a video call. Verification also runs through the VNeID app and the operator apps.
Which operator suits a resident: Viettel, Vinaphone or MobiFone?
Viettel has the widest coverage, including mountains and islands, so I would pick it for motorbike trips in the north or island stays. Viettel, Vinaphone and MobiFone all support eSIM, and Vinaphone and MobiFone are strongest in cities. In Hanoi, Ho Chi Minh City and Da Nang the three perform similarly, so the nearest branded shop usually decides.
How much does a month of mobile data cost?
A tourist-grade month costs about $6 to $8 and buys 30 days with 3 to 6 GB a day. Viettel’s ST90K plan, for example, gives 6 GB a day for 30 days at $8. Resident bundles of 3 to 12 months work out cheaper per month, though operators change them often, so confirm the price on the operator’s site before paying. I prefer paying month by month until you know which operator holds a signal at your door, and only then lock in a longer bundle.
| Where you buy | Typical price | Best for |
|---|---|---|
| Airport desk in Da Nang, 2026 | $10 to $13 | first 24 hours |
| City shop | from about $6 | daily use |
| 3 to 12 month resident bundle | from about $3 per month, check the operator site | long stays |
The rest of a monthly budget is broken down in the cost of living in Da Nang.
Can you keep your home number and use eSIM in Vietnam?
Yes: with a dual-SIM phone or an eSIM, the Vietnamese number takes the second slot and the home number stays on the first, so bank texts keep arriving. On a phone with one physical slot, the Vietnamese SIM pushes out your home SIM. I treat a second slot or an eSIM as non-negotiable for exactly this reason, because a bank code sent to a SIM lying in a drawer never reaches you.
All three operators issue eSIM, and Viettel converts a plastic SIM to eSIM in a shop or through My Viettel. A local eSIM with a Vietnamese number needs the same passport registration. International data-only eSIM apps carry data only, with no Vietnamese number or SMS.
Number portability between Viettel, Vinaphone and MobiFone has existed since November 2018. It moves a Vietnamese number between local operators, and the operator quotes the current fee and timing when you apply.
What else should you sort out in your first week?
Alongside the SIM, a long stay needs a bank card, home internet and a visa plan. The card and the internet are paperwork you can finish yourself, while your permitted days start counting on the day you enter and keep running while you set up.
For the practical order of tasks, use the first-week relocation checklist, the guide to a Vietnamese bank card on an e‑visa and the breakdown of home internet in Da Nang.
The visa clock is where long-stayers get caught, because an overstay ends in a fine and an awkward conversation at the border. The e‑visa form on evisa.gov.vn takes one evening to fill in, and the portal often rejects foreign cards at the payment step. At BestBus Vietnam I handle 90-day e-visas end to end: I fill the form, pay the fee with a card that clears and pick the right entry point. Ask me on WhatsApp to file your 90-day e‑visa, and I will check which entry point suits your route.
What happens if you skip verification or change phones?
An unverified number first loses outgoing calls, then is blocked completely, and 5 days later the operator terminates the contract and reclaims the number. SIMs issued before April 15, 2026 had 60 days to be re-verified. Write-ups describe the ladder for foreigners on passports differently, so verify right away.
Changing handsets also triggers a check: within 2 hours the operator blocks outgoing calls and texts, and you get 30 days to repeat the face check before full blocking. This applies to most subscribers from June 15, 2026. How long an inactive number survives depends on the operator and plan, so ask the shop for the exact term when you buy.
Bottom line: what to buy for a long stay
Go to an operator desk or a branded Viettel, Vinaphone or MobiFone shop with your original passport and let them photograph your face on the spot. Keep your home number alive in a second slot or an eSIM, since bank codes still go there. After that, set a monthly top-up reminder and look at the number’s status in the operator app whenever you change phones.
A SIM takes one visit to an operator shop, and the e‑visa form on evisa.gov.vn you can file yourself, but a passport stamp cannot be extended in a phone store. When your visa-free days or e‑visa have a week or two left, send me your entry date and city on WhatsApp and I will tell you whether to extend, apply for an e‑visa or plan a border run.
Frequently asked questions
Is there a limit on how many SIMs one passport can hold?
The rule for one document is up to three prepaid SIMs per operator. A fourth requires a contract with the operator.
Is it safe to buy a SIM from a street seller?
Street kiosks and resellers often sell SIMs registered to someone else’s data, and those numbers can be switched off. If nobody asks for your passport or photographs your face, the SIM is registered to a stranger.
How can I see which numbers are registered to my passport?
In the VNeID app open the document wallet and choose the phone number section. My Viettel, My VNPT and MyMobiFone also list the numbers held with each operator.
Are the airport SIM desks open at night?
Some desks in the arrivals hall close overnight and in the early morning. For a night arrival, carry an international data-only eSIM and buy the local SIM the next day in a branded shop.
