Can I use my own phone, and where do I get a SIM?
Short answer
Buy a prepaid SIM on arrival with your passport — it is cheap, the coverage is good, and a local number is what makes the ride-hailing apps work.
Three networks, one document
Viettel, Vinaphone and Mobifone are the three GSM operators, and the tourism board notes all three have good coverage. Prepaid SIMs are sold on arrival at the major airports and from countless shops afterwards.
The passport is the requirement: you have to show it to register the SIM. That is the only friction in the process — no appointment, no waiting list, just the document you are already carrying.
What it costs, and how topping up works
The tourism board calls prices for SIMs, texts and calls extremely affordable. Credit loads in increments from 20,000 to 100,000 dong on most networks, and a data-only SIM typically runs 100,000 to 200,000 dong depending on the allowance.
Against the price of a single taxi ride, connectivity here is close to a rounding error. There is no reason to ration it or to rely on café wifi for a whole trip.
Why the local number matters more here
This is not just about maps. Grab and the other ride-hailing apps need a Vietnamese SIM to work properly, because the account and the driver's contact both run through a local number.
So the SIM is not a convenience purchase — it is the thing that unlocks the most useful way to move around a city where flagging the wrong taxi is the main avoidable mistake. Buy it at the airport before you need your first ride.
Good to know
- Passport required to register the SIM — buy it at the airport on arrival
- Ride-hailing apps need a Vietnamese number to work properly
- Data-only SIMs run roughly 100,000–200,000 dong
Yes. A prepaid eSIM is usually far cheaper than roaming — but it gives you data only, not a Japanese number.
Yes, but decide how before you fly. A local SIM has to be registered against your passport, and a number of services you use daily will not load.
Yes, if the handset is unlocked — and bring your passport, because every SIM here is registered to a named person.
Yes, and you may barely need data — free public Wi-Fi runs on subway trains, buses and in most cafés.
There is a genuine national free wifi network — iTaiwan, over 5,000 hotspots, and since 2020 no registration at all. Connect, open a browser, done.