Japan SIM Card for International Students: Setup Guide

A newcomer to Japan needs a residence card and a registered address before most carriers will open a monthly phone plan, so the first weeks are usually covered by a prepaid SIM or a data eSIM. A data only eSIM bought before the flight keeps maps, messaging and internet calls working while the paperwork catches up.

Japan SIM card for international students: what you need

The short answer: you need a residence card (zairyu card), a registered Japanese address and a way to pay monthly before a carrier will give you a normal contract. Until then, a prepaid SIM or a data eSIM covers you.

What the main networks ask for:

• A residence card with enough remaining period of stay. KEK says at least 90 days from the application date.
• Your passport.
• A Japanese bank account (bank book) or a credit card in your own name for the monthly payment.
• A registered Japanese address.

Things to know before you apply:

• The card name, address and date of birth must match the application (KEK).
• Some providers refuse foreign issued credit cards.
• Budget (kakuyasu) SIMs usually need a residence card and a credit card in your own name (Hokkaido University).
• Tohoku University says people staying under 3 months generally cannot sign a contract.
• Major carrier contracts are often two years with early termination fees (Hokkaido University).

Identity checks are tightening. The Mobile Phone Improper Use Prevention Act already requires identity checks for voice enabled SIMs, and a 2026 amendment extends checks to data only SIMs (MIC White Paper 2026). Under MIC Ordinance No. 94, from 1 April 2027 in person contracts must read the IC chip on the ID document rather than only looking at the card. The date data only checks start is not confirmed, so confirm with the operator. See the Japan plan page for a data option that needs no paperwork.

Prepaid SIM or monthly contract: which comes first

Prepaid comes first for most newcomers. It needs only ID, works from day one and carries no cancellation fee. A monthly contract is the better long term home once your residence card, address and payment method are in place.

Prepaid:

• Sold at airport counters, carrier shops and electronics stores.
• Stores ask for a residence card and some accept a foreign passport (Hokkaido University).
• Prepaid credit can be topped up at phone shops and convenience stores.
• Short stay visitors are generally pointed to prepaid or travel eSIMs before they hold a residence card.

Monthly contract:

• Budget SIM (MVNO) plans come as data only, data plus SMS, or data, SMS and voice.
• Hokkaido University says budget SIMs can be cancelled at any time without fees, unlike the two year major carrier contracts.
• Rakuten Mobile sign up is reported by third party guides to accept a residence card (or Special Permanent Resident Certificate) online and to offer eSIM, and to accept international credit cards. Rakuten's own eligibility rules, such as minimum stay or passport only sign up, are not confirmed, so check with Rakuten.
• Main carrier eSIM rules for passport only customers are not confirmed.

If you want a data connection while you decide, an eSIM for Japan can be installed before you fly and does not touch your contract options.

How long the paperwork takes

The residence card is usually issued on arrival at the major airports; elsewhere it arrives by post after you register an address. The address notification is due within 14 days, and a certificate of residence can usually be issued within 2 days of notifying, which is often enough to open a bank account or buy a phone.

Step by step:

1. Residence card. Issued on arrival at Narita, Haneda, Chubu, Kansai, New Chitose, Hiroshima and Fukuoka airports. Arrivals at other airports get it by post after registering an address. Note that Hokkaido University says direct arrivals at New Chitose do not get one on entry, which conflicts with Iwate University's list, so ask at the airport.
2. Moving in notification at the city or ward office. Due within 14 days of deciding on a residence.
3. Certificate of residence (juminhyo). Usually issued within 2 days of notifying the address, and usable for a bank account or a phone purchase before the card arrives.
4. Bank account. People with a period of stay under 6 months are treated as non residents and usually cannot open an ordinary account. Japan Post Bank opens accounts without the 6 month requirement, but transfer and remittance functions are restricted until 6 months of stay. That is university guidance; Japan Post Bank's own page was not checked, so the exact restrictions are not confirmed.
5. Phone contract. Once you hold the card, address and payment method, apply at a carrier shop or online.

Budget days, not hours, for each step, and keep photocopies of every document.

Your first 30 days in Japan: a timeline

Days 1 to 3 are for arrival and a data connection, days 4 to 14 for the address notification and certificate of residence, and weeks 3 to 4 for the bank account and the phone contract. Expect the order to be address first, bank second, phone third.

• Before the flight: install a data eSIM and check your phone is unlocked and eSIM compatible with the compatibility checker.
• Day 1: collect your residence card at the airport if you land at one of the listed airports, and connect the eSIM on landing.
• Days 1 to 14: notify your address at the city or ward office and request a certificate of residence.
• Days 2 to 14: open a Japan Post Bank account if you are under 6 months, accepting the restricted transfer functions for now.
• Weeks 2 to 4: apply for the phone plan with your card, address and payment method.
• Ongoing: keep a prepaid or eSIM data line as backup while the contract is processed.

A data calculator helps you size the first month of data so you do not run out mid paperwork.

Staying connected until your local plan is ready

A data only eSIM is the simplest bridge. Slashtel eSIMs give data with no local phone number and no calls or SMS, and WhatsApp and other internet calls work over the data. Buy online, install before you fly, and the validity starts when it first connects in Japan.

How it works:

• Data options of 1, 3, 5, 10, 20 or 50 GB. The 5 GB plan starts from $5.39.
• Bought with an email address and a card, Apple Pay or Google Pay; the QR code arrives by email within minutes.
• Someone else can buy it and enter the traveller's email, so the code goes straight to the user.
• Validity starts on first connection at the destination, so it can be bought and installed at home.
• The network is chosen automatically and cannot be picked by hand.
• More data can be added to the same eSIM later, with no new QR code.
• The phone must be unlocked and eSIM compatible.
• Support is on WhatsApp and email, 7 days a week.

Installation steps are in the iPhone and Android install guide. Remember Japan has no GSM network, so GSM only phones will not work at all (Hokkaido University).

Getting a local number for your bank and admin

You need a local number once banks, employers or the ward office want to call or text you, and a prepaid local SIM gives you one. The Slashtel eSIM does not: it is data only, with no number, calls or SMS.

When a number matters:

• Bank applications often want a phone number alongside a registered address.
• Some university and employer payments can be delayed until a Japan Post Bank account is switched to resident status (Kyushu University), and staff may need to reach you.
• Contracts and identity checks are tied to a number you control.

How to get one:

1. Register your address and get a certificate of residence.
2. Buy a prepaid SIM with voice at a carrier shop or electronics store, with your residence card or, where accepted, your passport.
3. Later, move to a monthly contract when your bank account or Japanese credit card is ready.

Watch the loop: contracts usually need a bank account or Japanese credit card, Japanese card issuers usually want a Japanese mobile contract, and prepaid numbers are often rejected at that check (third party guide). Solve it with Japan Post Bank first. For how data and codes work together, read calls, texts and OTPs.

When family visits you in Japan

Visiting family can use a Slashtel eSIM for the trip. You can buy it from Japan and enter the visitor's email, so the QR code goes straight to their phone before they fly, and they land connected.

Practical points:

• Choose a data size to match the visit; 1, 3, 5, 10, 20 and 50 GB options exist, and the 5 GB plan starts from $5.39.
• The eSIM is data only, so calls home go over WhatsApp or similar internet calls.
• Install and test at home, since validity starts on first connection in Japan.
• Check the visitor's phone is unlocked and eSIM compatible first.
• For a longer stay, a prepaid SIM from an airport counter or electronics store is the local option, with a passport accepted at some stores.

This keeps a sim card for parents visiting Japan simple: no shop visit, no paperwork, no local number needed for a short trip.

Keeping your home number active

Keep your home SIM in the phone for calls and bank codes, and turn off data roaming on it to avoid roaming charges. If it is prepaid, top it up so the line is not cut while you are in Japan.

How to run both lines:

• Set the Slashtel eSIM as the data line and the home SIM for calls and SMS.
• Turn off data roaming on the home SIM in the phone settings.
• Use the home number for one time codes from your home bank and for family calls.
• Slashtel sells mobile top ups to more than 100 countries, delivered in minutes, which keep a prepaid home line active; see top ups.
• If you later want a long term data line without a local contract, monthly eSIM options exist.

More detail is in keeping your number active.

First-week catches to avoid

Most first week problems come from the order of the paperwork, not from the phone. Register the address first, get a certificate of residence, then open the bank account, then the phone contract.

• Do not buy a phone plan before you have an address and a payment method; the application will stall.
• Do not rely on a foreign credit card everywhere; some providers refuse foreign issued cards.
• Do not assume a GSM only handset will work; Japan has no GSM network (Hokkaido University).
• Do not expect full banking in the first 6 months; Japan Post Bank accounts have restricted transfers until then, and some payments can be delayed (Kyushu University).
• Do not miss the 14 day window for the moving in notification.
• Do not leave home without data; a data eSIM installed before the flight avoids airport queues.

For the wider relocation checklist, see moving abroad.

Sources

Checked 2026-10-24. Rules and waiting times change, so check the official sites before you rely on them.

• Ministry of Internal Affairs and Communications: https://www.soumu.go.jp/johotsusintokei/whitepaper/ja/r08/html/nd222640.html
• Miyake & Partners (law firm commentary): https://www.miyake.gr.jp/wp-content/uploads/2026/07/AMLCFTニュースNo2_携帯電話不正利用防止法施行規則改正.pdf
• Ministry of Internal Affairs and Communications: https://www.soumu.go.jp/tokushusagi/id-check/
• Hokkaido University: https://www.global.hokudai.ac.jp/campus-life/living-costs-and-tips/your-mobile-phone/
• KEK Users Office: https://www2.kek.jp/rso/test/eng/BeforeCome/Cellphone.html
• Iwate University: https://ivs.iwate-u.ac.jp/en/long/arrival/
• Kyushu University: https://isc.kyushu-u.ac.jp/invitation/support/dailylife.php
• Study in Japan (JASSO): https://studyjapan.jp/en/topics/life/bankaccount.html
• Tohoku University: https://sup.bureau.tohoku.ac.jp/?p=150
• Selectra Japan (third party): https://selectra.jp/en/sim/apply-for-rakuten