Required Documents for Naturalization in Japan | Case-Based Checklist & Key Points

Many people searching for “required documents for naturalization in Japan” feel uncertain about where to start and which additional documents apply to their specific situation. Compared to other immigration procedures, naturalization requires a large number of documents, and even a single missing or incorrect document may result in the application not being accepted at all.

This page organizes a comprehensive checklist of required documents for naturalization based on practical operation as of 2025. Start by confirming the common basic documents, then review the additional documents required depending on income, family situation, and residence history.

Please note that the actual documents required may vary depending on the Legal Affairs Bureau in charge and the applicant’s individual circumstances. The information provided here is a general guideline only, and you should always follow the instructions of your competent Legal Affairs Bureau.

1. Basic Required Documents for Naturalization (Common to All Applicants)

First, these are the documents required in almost all naturalization applications. They form the “foundation” of the naturalization process, so starting preparation early will help ensure a smooth application.

• Application for Permission of Naturalization (official form provided by the Legal Affairs Bureau)
• Curriculum Vitae (including educational background, employment history, and residence history)
• Statement outlining relatives (parents, siblings, spouse, children, etc.)
• Written Oath
• Photographs (specified size, taken within the designated period)
• Copies of Residence Card and Passport
• Resident Record (Jūminhyō) for all household members, without My Number
• Documents proving nationality (such as a certificate of items recorded on the alien registration record, as instructed by the Legal Affairs Bureau)

These documents constitute the core of the required documents for naturalization and are used to verify the applicant’s identity, residence status, and family composition. In particular, documents showing family relationships are closely linked to the home-country documents described below.

2. Documents Related to the Applicant and Family (Home-Country Issued Certificates, etc.)

Next are documents used to prove the applicant’s and family members’ personal status. In many cases, these must be obtained in the applicant’s home country and submitted with a Japanese translation, making this one of the most time-consuming parts of preparation.

1. Required documents related to the applicant

• Birth Certificate
• Certificate of nationality or documents equivalent to a family register
• Marriage Certificate (if married)
• Divorce Certificate (if there is a history of divorce)
• Documents proving any name changes, if applicable

These documents are used to confirm the applicant’s parentage and marital history. As document names and acquisition methods vary significantly by country, it is advisable to proceed after receiving specific guidance from the Legal Affairs Bureau or a professional.

2. Required documents related to family members (spouse, children, etc.)

• Birth certificate and nationality certificate of the spouse
• Birth certificates of children (may be required from both Japan and the home country)
• If the spouse is Japanese, a copy of the Japanese spouse’s family register (koseki)

If family members hold multiple nationalities or if there are children from a previous marriage, additional documents may be required. Family relationships are a critical element in naturalization screening, so carefully check that there are no inconsistencies or omissions.

3. Documents Related to Income and Employment (Employees and Self-Employed Applicants)

In naturalization applications, documents related to income and employment are essential to determine whether the applicant can maintain a stable livelihood in Japan. This is one of the most important sections among the required documents for naturalization.

1. Salaried employees (company employees, contract workers, dispatched workers, etc.)

• Withholding tax slips (typically for the most recent one to two years)
• Pay slips (several months’ worth may be required)
• Certificate of employment and/or employment contract
• Company profile of the employer (brochure, website printout, etc.)

These documents are used to confirm employment type, length of service, and income stability. Applicants who have changed jobs frequently or experienced changes in employment status may be asked to explain the circumstances.

2. Self-employed individuals, freelancers, and business owners

• Copies of final tax returns (usually about three years)
• Tax payment certificates (income tax, business tax, etc.)
• Documents describing the business (commercial registry, articles of incorporation, business licenses, etc.)
• Financial statements such as profit and loss statements and balance sheets (for corporations)

For self-employed applicants and business owners, explanations of financial figures are often required. Therefore, it is important to organize tax accountant-prepared documents and financial statements in advance. If income fluctuates significantly, additional written or oral explanations about the business situation may be requested.

4. Required Documents for Taxes, Pension, and Social Insurance

In a naturalization application, tax payment and social insurance compliance are checked very strictly. Among the required documents for naturalization in Japan, the sections related to taxes, pension, and health insurance have become especially important in recent years.

1. Tax-related documents

• Resident tax (jūminzei) taxation certificate and tax payment certificate (issued by your municipality)
• Income tax payment certificate (may be required for self-employed applicants or high-income earners)

Unpaid taxes or installment payments can be a major negative factor for naturalization. We strongly recommend that you check your payment status in advance and, if necessary, complete all payments before applying.

2. Pension and health insurance documents

• Pension enrollment records (Nenkin Teikibin and/or record inquiry at the pension office)
• Certificate of health insurance enrollment
• Documents showing premium payment status (if required)

If you have a long period of non-enrollment or non-payment for pension, authorities may conclude that you have not fulfilled your obligations as a member of Japanese society. In recent years, the enrollment and payment status of social insurance, including pension and health insurance, has been heavily emphasized—so reviewing this early is highly recommended.

5. Documents Proving Housing and Living Conditions

To confirm that you have a stable living base in Japan, documents related to your housing situation are also required.

• Resident Record (Jūminhyō) for all household members
• Lease agreement (for rental housing)
• Housing loan-related documents (for homeowners)
• Documents showing information about cohabiting family members

The income and residence status of family members living with you may also affect the evaluation of your naturalization application. Especially if you support a spouse or children, organize your documents so it is clear who supports the household and how living expenses are covered.

6. Additional Documents by Case (Common Patterns)

This section addresses the commonly searched keyword “required documents for naturalization in Japan by case”. Depending on your circumstances, additional documents may be required in the following situations.

1. If you are married to a Japanese national

• Family register (koseki) of the Japanese spouse
• Documents showing the marital relationship and cohabitation status
• Documents relating to the couple’s income, taxes, and pension status

If you live primarily on your spouse’s income or you are a full-time homemaker, you may be asked to submit your spouse’s tax and pension documents as well.

2. If you have children

• Child’s birth certificate and/or family register (for children born in Japan)
• Documents showing educational status (a certificate of enrollment may be requested)

Whether the family as a whole is settled in Japan is an important factor in naturalization screening.

3. If you have a history of divorce or remarriage

• Divorce judgment and/or divorce certificate
• If you have children from a previous marriage, documents proving the family relationship

If there are omissions or inconsistencies in information related to previous marriages or remarriage, the screening may take longer and you may be repeatedly asked for additional documents.

4. If you are unemployed, changed jobs frequently, or mainly worked part-time

• Documents explaining your recent living expenses (bank balance, remittance proof, etc.)
• Documents explaining job changes and your current employment status

If your income is unstable, you will need to provide a convincing explanation to show that you can continue to live stably in Japan going forward.

7. Document Preparation Flow and Key Notes (2025 Edition)

For naturalization, it is not enough to simply collect documents—you must also pay attention to validity periods and consistency of information.

• Many certificates should be issued within about “3 months” as a general guideline
• Foreign-language documents must be accompanied by a Japanese translation, with the translator clearly identified
• Check for consistency across residence history, address history, employment history, and marital history
• Confirm in advance that there are no unpaid taxes, pension, or health insurance premiums

Because obtaining documents from your home country can take time, it is efficient to follow this flow: prepare home-country documents → obtain Japanese certificates → consult the Legal Affairs Bureau in advance → submit the full application.

8. Summary: The Key Is “Listing” and “Prioritizing” Required Documents

When you search for “required documents for naturalization in Japan”, you will find a lot of information online. The most important step is to organize what is required for your specific case as early as possible.

• Common basic documents (application forms, CV, residence card, resident record, etc.)
• Identity and family relationship documents (birth, nationality, marriage-related documents)
• Income, employment, and business-related documents
• Certificates for taxes, pension, and health insurance
• Documents showing housing and living conditions
• Additional documents by case (marriage, divorce, children, unemployment periods, etc.)

If you create a checklist and decide what to obtain, from where, and by when, your naturalization preparation will become much more manageable.

At ACROSEED Immigration Lawyer's Office, we help first-time applicants avoid confusion by preparing a personalized required-document list and supporting the collection process based on each client’s situation. If you are unsure where to start, please feel free to contact us.

9.Related Pages Often Read Together with Naturalization Applications

[2025 Edition] Japan Naturalization Guide | Requirements, Documents & Application Process

A clear and comprehensive guide covering the latest 2025 requirements, required documents, key review points, application flow, and interview preparation. Also explains nationality renunciation considerations, FAQs, and three service plans.

Naturalization Guide for Spouses of Japanese Nationals

Naturalization through marriage generally requires 3+ years of marriage history and 1+ year of residence in Japan (as a rule). Learn key review points such as the “genuineness of marriage,” “financial stability,” and “Japanese language ability,” plus how cases with children are assessed and common refusal patterns.

Naturalization from a Work Visa (Engineer/Specialist in Humanities/International Services)

Detailed explanation for foreign employees: requirements, required years, income standards, and how changing jobs affects screening. Covers differences based on employment style and tax status, the latest trends in review timelines, and practical strategies to avoid refusal.

Naturalization Guide for Highly Skilled Professional (HSP) Visa Holders

For applicants considering naturalization from HSP (Type 1 / Type 2). Explains situations where screening may be relatively favorable, and factors that require extra caution (e.g., research-track roles, job stability, and continuity of activities).

Naturalization Guide for Business Manager Visa Holders

Experts explain common stumbling points for business owners: business stability, tax compliance, executive compensation design, and social insurance handling. Includes review tendencies reflected from 2025 onward.

Naturalization Guide for Permanent Residents

The final step for permanent residents to become Japanese nationals. Organizes required documents, review timelines, and how decisions differ by family structure, plus preparation to avoid refusal and a clear comparison of “Permanent Residence vs Naturalization.”

Naturalization Guide for Long-Term Resident Visa Holders

For Long-Term Residents (spouse-based long-term, child of a Japanese national, stepchild, Nikkei-related statuses, etc.). Explains key requirements, documents, what examiners focus on, and Japanese language expectations by typical case type.

Naturalization Guide for Special Permanent Residents

Covers background of the制度, screening characteristics, how to write the reason statement for naturalization, and important notes about nationality choices within the family—tailored for Special Permanent Residents.

More In-Depth Questions About Japan Naturalization

Naturalization vs Permanent Residence in Japan: A Complete Comparison (2025)
Can You Apply for Naturalization with Less Than 3 Years of Work? Latest Standards & Approval Points
Naturalization and Time Outside Japan: Guidelines for “5+ Continuous Years” and Key Cautions
Naturalization Required Documents List: 2025 Latest Checklist by Case Type
Naturalization Requirements (7 Conditions): Expert Guide to Obtaining Japanese Nationality
My child has dual nationality (Japan & the U.S.). Are any procedures required?
Should You Hire an Administrative Scrivener for Naturalization? Benefits, Fees, and How to Choose
Income Requirements for Naturalization: How Much Is Needed and How “Ability to Support a Living” Is Judged
Traffic Violations & Minor Offenses in Naturalization: Do Parking Tickets or Criminal Records Matter?
Required Japanese Level for Naturalization: Speaking, Reading/Writing, and Interview Benchmarks
Are Taxes, Insurance, and Pension Critical for Naturalization? Does Non-Payment Lead to Refusal?
Renunciation of Prior Nationality: Country-by-Country Guidance (China, Korea, U.S., and More)
Residence Years & Time Abroad for Naturalization: 5-Year / 3-Year Rules and Key Judgment Points
Reasons for Naturalization Refusal: Common “Rejected at Intake” Cases and Timing to Reapply

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