eSIM or physical SIM · Japan number
au (KDDI)
A Japanese carrier whose lines receive texts abroad for free. au Kaigai Hōdai sells unlimited data at ¥1,200 per 24 hours, or ¥800 if booked ahead.
- Checked October 10, 2026
Where it works
Only the markets where the carrier's own pages say the SIM receives texts or uses data are listed. A market that is missing is one the carrier does not say it works in.
| Market | Receiving texts | Mobile data |
|---|---|---|
| Mainland China | Through roaming | Paid for on top |
| Hong Kong & Macau | Through roaming | Paid for on top |
| United States | Through roaming | Paid for on top |
| Taiwan | Through roaming | Paid for on top |
| Japan | On its own network | On its own network |
How to keep it working
An au line can receive texts abroad at no charge, and sending one costs ¥100. The US mainland, China, Taiwan and Hong Kong are all on au's list of countries for data, voice and SMS. For data, au Kaigai Hōdai (au海外放題) costs ¥1,200 per 24 hours without a booking in every covered country. Booking ahead in the app from Japan brings it to ¥800 per 24 hours in places such as the US, Taiwan and Hong Kong and to ¥1,000 elsewhere, China included, and a booking can be changed or cancelled up to an hour before it starts. An au line needs the free Data Charge option for it to apply; without it, the overseas double flat rate (up to ¥1,980 or ¥2,980 a day) applies instead.
Where this comes from
Compiled from the carrier's own public pages. Open them to check a fact before you rely on it.
- The rule Open the page (www.au.com) (checked October 10, 2026)
Compiled from each carrier's public pages and checked on the date shown. Rules and prices change without notice, and the carrier's current terms always prevail. General information only, not advice.
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