If your spouse, partner, or family member is moving in with you in Japan, you may need to officially add them to your apartment lease. Many foreign residents assume this is automatic — it is not. Adding a co-tenant or family member to an apartment lease in Japan requires your landlord's permission, and skipping this step can cause serious problems later. This guide walks you through exactly what to expect, what documents you need, and how to approach the process with confidence.
Why You Need to Tell Your Landlord
In Japan, your lease agreement (賃貸借契約) typically specifies who is permitted to live in the property. Quietly moving someone in without notifying your landlord or real estate agency (不動産屋) is considered a breach of contract in most cases. This matters for several practical reasons:
- Your landlord or guarantor company may conduct periodic checks on the registered occupants.
- If an incident occurs (fire, injury, damage), having an unregistered occupant can complicate insurance claims.
- At the end of your lease, disputes over the security deposit can become harder to resolve.
- Some guarantor companies (保証会社) require updated occupant information and may cancel your guarantee if they find discrepancies.
The good news is that in most cases — especially for a spouse, registered partner, or dependent child — landlords are willing to approve the change. It is largely an administrative process, and approaching it openly is always the safest path.
Who Counts as a Co-Tenant vs. a Visitor?
There is no single legal definition, but as a practical rule: if someone will be living with you continuously for more than about one to two months, they should be registered as an occupant. A friend staying a few nights is a visitor. Your spouse relocating from abroad is a co-tenant. When in doubt, notify your landlord — it costs nothing and protects you.
Step-by-Step: How to Add a Family Member or Co-Tenant to Your Lease
Step 1 — Check Your Existing Lease Agreement
Before contacting anyone, read your lease. Look for sections on 同居人 (co-residents) or 転貸 (subletting). Most leases require written landlord approval to add any co-resident. Note any specific conditions or forms mentioned. If your lease is in Japanese and you cannot read it fully, ask a bilingual friend or contact your local international support centre for help — do not guess.
Step 2 — Contact Your Real Estate Agency or Landlord
In Japan, most tenants communicate through the real estate agency (仲介業者) that arranged the original lease, rather than directly with the landlord. Call or email them to explain your situation simply: "I would like to add my [spouse / child / family member] to the lease as a co-resident. What do I need to do?" Most agencies deal with this regularly and will guide you from there.
If you managed directly with the landlord, contact them the same way. Be polite and straightforward — this sets a cooperative tone for the whole process.
Step 3 — Submit a Formal Application
You will typically be asked to fill out a co-resident notification form (入居者変更届 or similar). Requirements vary by landlord and guarantor company, but you can generally expect to provide:
- Full name of the person moving in
- Their relationship to you (spouse, child, parent, etc.)
- Their nationality and visa status
- A copy of their residence card (在留カード) if they already have one
- A copy of your updated residence certificate (住民票) showing both names at the same address — you will obtain this from your local city office after completing resident registration
- In some cases, proof of relationship (marriage certificate with a certified translation, family register, etc.)
Requirements differ, so confirm the exact list with your agency or landlord. This is general guidance — always ask what they specifically need.
Step 4 — Update the Resident Registration (住民票)
Your family member will need to register their address at your local city hall (市区役所) within 14 days of moving in. This is a legal requirement under Japan's Basic Resident Registration Act, separate from the lease process. Bring their passport, visa, and residence card. Once registered, you can obtain a 住民票 (residence certificate) listing all registered residents at your address — this document is often required by landlords as proof.
Step 5 — Notify Your Guarantor Company if Applicable
If your lease uses a guarantor company (保証会社) rather than a personal guarantor, you may need to notify them separately. Some companies charge a small update fee; others simply require a form. Ask your real estate agency whether this applies to your situation — do not assume it is handled automatically.
What If Your Landlord Refuses?
For immediate family members such as a spouse or child, refusal is uncommon and, in some interpretations, difficult to justify under Japanese tenant protection principles. However, lease terms vary. If you face resistance, remain calm and ask for the specific reason in writing. You may wish to consult the Japan Housing Finance Agency's tenant consultation service or your local legal affairs bureau (法務局) for free guidance. Avoid moving the person in without approval while a dispute is ongoing.
Common Documents Checklist
| Document | Who Provides It | Purpose |
|---|---|---|
| Residence card (在留カード) copy | The person moving in | Confirms legal residency status in Japan |
| Updated 住民票 (residence certificate) | City hall, after registration | Proves the new occupant is officially registered at your address |
| Proof of relationship | You (marriage cert, family register, etc.) | Shows the person is a legitimate co-resident, not a subtenant |
| Co-resident application form | Provided by your agency or landlord | Official notification to the property owner |
A Few Practical Tips
- Do everything in writing. Even if your agency calls you, follow up by email to create a paper trail.
- Keep copies of everything you submit and receive back.
- Do not delay. Register your family member at city hall promptly — the 14-day deadline is a legal requirement, not a suggestion.
- Language barrier? Many city offices have multilingual support, and some municipalities offer consultation services in English, Chinese, and other languages. Call ahead to check.
Summary: Adding a Co-Tenant Is Manageable — Just Follow the Steps
Adding a spouse, partner, or family member to your apartment lease in Japan is a routine process when handled correctly. The key points are: check your lease first, notify your landlord or agency before the person moves in, submit the required documents, and register the new occupant at your local city hall. Most landlords are cooperative, especially for close family members, and approaching the process openly makes everything smoother.
It may feel daunting when your Japanese is limited, but the steps are clear and the support is there. Take it one step at a time, get everything in writing, and do not hesitate to ask your city office or local international support centre for help — that is exactly what they are there for. You have got this.