Arriving & settling
Arriving in Japan: Connectivity, SIM Cards, and Your First Phone Contract
How to get connected on day one and choose a mobile contract in your first month: what identification providers ask for, how address registration affects sign-up, and where to verify current plans.
Key takeawayGet a newcomer online immediately on arrival, then help them choose a contract mobile plan using only provider-published information, without quoting prices that change.
1. Day one: get data before you have a Japanese address
On arrival day you mainly need maps, translation, and a way to contact your accommodation or sponsor. Practical options are an international eSIM or roaming plan activated before departure, or a short-term visitor SIM sold at airports and electronics stores. These are data products for visitors; treat them as a bridge, not your long-term contract.
Practical sequence: 1) Before departure, confirm your phone is unlocked and supports eSIM if you plan to use one. 2) Download offline maps and your accommodation address in Japanese (住所) before you fly. 3) Activate the bridge data product on landing and test it before leaving the airport, while staff and information desks are nearby. 4) Save screenshots of your address, sponsor contact, and residence card in case connectivity drops.
Prices, data allowances, and eligibility for visitor products change frequently and differ by provider. Verify the current offer on the provider's own page before purchase — this guide deliberately quotes no yen figures for plans.
2. Why address registration usually comes before a contract plan
Contract mobile plans (契約, keiyaku) in Japan are identity-checked contracts. Providers typically ask for a residence card (在留カード) showing a registered address, and many ask for a Japanese bank account or credit card for monthly payment. This is why our arrival journey puts city hall registration (転入届) before a long-term phone contract.
If a provider's shop (店舗) cannot complete a contract because an item is missing, ask exactly which document is needed and whether a different plan type is available to you. Requirements differ between the major carriers — NTT DOCOMO, au by KDDI, and SoftBank — and low-cost brands, so verify the identification list on the provider's official page or in-store guidance rather than relying on forum posts.
Keep your name consistent everywhere: the roman-letter spelling on your residence card should match what you give the provider, your bank, and your employer. Inconsistent spellings are a common, avoidable cause of failed identity checks.
3. Choosing a plan: compare on the provider's own pages
Compare plans only on official provider pages, checking the same five points each time: monthly data allowance and what happens when you exceed it, whether voice calls and a Japanese phone number (電話番号) are included, contract term and cancellation conditions, identification and payment requirements for foreign residents, and whether international services you need are supported. Verify all prices at the source at the time you apply.
The Ministry of Internal Affairs and Communications (総務省) publishes consumer information on telecommunications services, including SIM unlocking and number portability (MNP). If you bring a handset from abroad, confirm with the provider that your device works on their network and is legally usable in Japan before signing.
Practical sequence: 1) Shortlist two providers with shops near your home or workplace. 2) Visit with your residence card, passport, and payment method, and ask for the total first-month and monthly costs in writing. 3) Read the contract summary (重要事項説明) before signing, especially cancellation and handset-payment terms. 4) Keep the customer number and support contact; you will need the phone number for bank accounts, deliveries, and two-factor authentication.
4. After sign-up: make the number work for daily life
Once you have a Japanese number, update it everywhere promptly: employer or school, bank, city hall contact details if requested, delivery services, and your housing manager. Many Japanese services use the mobile number for identity confirmation, so changing numbers later is disruptive — choose a plan you can keep.
For home internet, note that rental properties vary: some include internet, others require a separate contract with a line provider and an internet service provider, which can take time to install. Ask your landlord or management company what is already installed before ordering anything, and verify installation steps and costs with the provider directly.
If you lose your phone or SIM, contact the provider's official support channel immediately to suspend the line; contact details are on the provider pages linked here. Keep your residence card separate from your phone so one loss does not become two.
Sources
- Ministry of Internal Affairs and Communications (総務省)Ministry of Internal Affairs and Communications — Telecommunications policy (English)
- NTT DOCOMO, Inc.NTT DOCOMO — English site
- KDDI Corporationau (KDDI) — English site
- SoftBank Corp.SoftBank — English site
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