Can I use my own phone here?
Short answer
Yes, if it is unlocked — and that is the one thing you cannot fix after you land. There is no passport registration to do here; a local eSIM plan is bought in an app in a few minutes.
Unlocking is the only real prerequisite
The FCC explains the mechanism in its consumer guidance: a locked handset is restricted by the carrier that sold it, and unlocking is something that carrier does. Ask them before you fly, because the request is far harder to make from another country and a locked phone will not take a local plan at all.
Unlocked is not the same as compatible. A phone also has to support the radio bands the local networks use, which is worth checking against your model for anything more than a few years old.
No paperwork, unlike much of Asia
Travellers arriving from China, Thailand or Vietnam expect to register a SIM against a passport. There is nothing equivalent here for a visitor prepaid plan — you buy it, you activate it, you are on.
That makes the eSIM route the simple one. Buy a plan before you land or on arrival, activate it over wifi, and keep your home number on the physical SIM for messages.
If you would rather not bother
A short trip in one city can be done on wifi alone, with the next question covering where that is. It is workable, and it is worse — no data on the street means no maps while walking and no ride-hailing app where you actually need one.
The middle path most people end up on is a small prepaid data plan and nothing else. Calls and texts run over apps, so a local voice number is rarely the thing you needed.
Good to know
- Ask your carrier to unlock the phone before you travel — it is hard to arrange from abroad
- No passport registration for a visitor plan, unlike China, Thailand or Vietnam
- An eSIM plan activates over wifi in minutes
- Check band compatibility on older handsets
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.
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.
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.