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eSIM for Japan, Korea, China and Taiwan — what to check before you buy
Short answer: an eSIM is the simplest way to get online in Japan, Korea and Taiwan — install it before you fly, switch it on when you land. Mainland China is the exception and needs a moment’s thought before you pick a plan.
| Where | How it usually goes | What to check first |
|---|---|---|
| Japan | Straightforward. Coverage is dense, including on the shinkansen. | Data-only plans give you no Japanese phone number. Some restaurant and ticket bookings want an SMS code. |
| South Korea | Straightforward. Among the fastest mobile networks anywhere. | Same no-phone-number caveat. Korean apps often verify by SMS. |
| Taiwan | Straightforward, cheap, good rural coverage. | Little to watch for. Check the daily cap if you tether. |
| Mainland China | Works, but the domestic network filters a large share of international services. | A travel eSIM that roams through a foreign carrier routes your traffic outside the domestic network, which is why most visitors use one. Confirm what your plan actually routes through before you buy. |
Verified 6 September 2026.
The three things that go wrong
- Phone not eSIM-capable or carrier-locked. Check both before buying — an eSIM cannot be refunded once installed.
- Installing on arrival. Install while you still have Wi-Fi at home. You cannot download an eSIM profile without a connection.
- Assuming you get a phone number. Most travel eSIMs are data-only. Keep your home SIM active for SMS, or plan around it.
Country guides
- Japan — eSIM, SIM cards and pocket Wi-Fi
- South Korea — eSIM, SIM cards and Wi-Fi
- China — phones, apps and mobile pay