Almost everyone hits the same wall in their first week. The bank will not open an account without a Japanese phone number. The mobile carrier will not open a contract without a Japanese bank account or credit card. Neither is being obstructive; they are separate commercial rules that happen to interlock.
Here is how the loop breaks.
Breaking the deadlock
The usual answer is an MVNO — a budget operator running on one of the big three networks — because several accept an overseas credit card as the payment method. That gives you a Japanese number without needing the account you cannot yet open, and the bank stops being a problem.
Confirm card acceptance before committing. It varies by operator, by plan and sometimes by card issuer, and finding out at the checkout screen wastes an afternoon.
The other route worth knowing is an eSIM, which can be bought and activated before you fly. No shop visit, no waiting for a card in the post, and no delivery address needed — useful precisely when you have not got one yet. Landing with a working Japanese number, on the day you need to call an estate agent or confirm a ward office appointment, removes a whole category of first-week friction.
Get a voice line
A voice line with a 090, 080 or 070 number is worth paying slightly more for. Banks, landlords, guarantor companies, employers and government services all use SMS verification and callbacks, and a meaningful number of them reject data-only numbers, IP numbers and app-based numbers outright.
A data-only plan is cheaper and will serve you fine for messaging. It will also, at some point, stop you completing a form that matters. Given the difference is small, take the voice line for the first year at least.
What you will be asked for
- Residence card — the standard identity document for a resident plan
- Passport
- A Japanese address, ideally already written on the back of your residence card
- A payment method — Japanese bank account, Japanese credit card, or with many MVNOs an overseas card
Some carriers also check that your residence card outlasts a minimum period. Not all do, and it varies, so a short remaining stay is worth asking about rather than assuming.
Big three or MVNO
The major carriers give you nationwide shops, in-person support and the strongest coverage in rural areas. An MVNO gives you a much lower monthly bill, more flexible payment options and usually an online-only process.
For a new arrival the practical trade-off is support versus price. If your Japanese is limited and you would rather sit across a desk from someone, the extra cost of a big-three shop contract buys a real service. If you are comfortable online and want the number today, an MVNO is faster and cheaper.
Compare on: current identity and payment rules, contract length and cancellation terms, whether English support exists at the point you would need it, and coverage where you will actually live rather than where you will visit.
Things worth checking before you sign
- Cancellation terms. Lock-ins have loosened but have not vanished.
- Whether the number is portable if you switch later. Keeping a number you have given to a bank and an employer is worth more than a small monthly saving.
- What happens when you leave Japan. Closing a contract from abroad is difficult; plan to do it in person.
- Tethering and data caps, if you work from home.
The phrases
- SIMカードを契約したいです。 — SIM kādo o keiyaku shitai desu. — I would like to sign up for a SIM card.
- 音声通話付きのプランはありますか。 — Onsei tsūwa tsuki no puran wa arimasu ka? — Do you have a plan with a voice line?
- 海外のクレジットカードは使えますか。 — Kaigai no kurejitto kādo wa tsukaemasu ka? — Can I use an overseas credit card?
- 契約の解約はいつでもできますか。 — Keiyaku no kaiyaku wa itsu demo dekimasu ka? — Can I cancel the contract at any time?
Where to confirm this
- Our guide to opening a bank account — the other half of this loop
- Our guide to registering your address
Guides are dated rather than undated: last reviewed 13 September 2026. This is an organisational aid, not legal or immigration advice — always confirm anything consequential with your ward office, the Immigration Services Agency, or a qualified professional.