Renunciation of Nationality in Japanese Naturalization Applications | Country-Specific Rules and Key Considerations

When considering a Japanese naturalization application, many applicants are confused about what happens to their current nationality once they acquire Japanese citizenship.

Common questions include: “Is renunciation of my original nationality mandatory?”, “Are there countries that allow dual nationality upon naturalization?”, and “If my home country does not permit renunciation, can I still naturalize in Japan?”

This page is intended for readers who already understand the overall framework and other requirements of Japanese naturalization. It provides a clear explanation of the basic rules regarding renunciation of nationality in naturalization applications and how these rules differ by country, focusing on major nationalities such as China, South Korea, Taiwan, and the United States.

Use this guide to understand what you should confirm and prepare before applying, especially if you have concerns about nationality renunciation.

1. Basic Rules on Japanese Naturalization and Renunciation of Nationality

1. Japan’s Naturalization System and the Principle of Single Nationality

Under Japan’s Nationality Act, dual nationality is generally not permitted. Therefore, when Japanese naturalization is approved, applicants are required, in principle, to renounce their previous nationality.

This concept is known as the “principle of single nationality”. Once Japanese nationality is acquired, the legal framework assumes that the individual cannot continue to hold another country’s nationality simultaneously.

2. When Is Renunciation of Nationality Required?

It is not mandatory for renunciation of nationality to be completed at the time of submitting a naturalization application. In most cases, the standard procedure is to renounce the original nationality after Japanese naturalization has been granted.

However, whether renunciation is legally possible and what procedures are required are examined at the application stage. For this reason, prior understanding and preparation regarding nationality renunciation are extremely important.

2. Why Some Countries Do Not Allow Renunciation of Nationality

1. Countries That Do Not Legally Permit Renunciation

In some countries, national laws do not permit renunciation of nationality, or allow it only under extremely limited conditions.

For applicants from such countries, Japanese authorities take into account the fact that renunciation may be legally or practically impossible.

2. Countries Where Procedures Are Extremely Difficult

Even where renunciation is theoretically permitted by law, there are countries where the actual procedures are highly complex and time-consuming.

In such cases, the Japanese naturalization review focuses not only on the fact that renunciation has not yet been completed, but also on whether the applicant is making genuine efforts toward renunciation.

3. Country-Specific Approaches to Renunciation in Naturalization Applications

1. Applicants with Chinese Nationality

Under China’s Nationality Law, dual nationality is generally not recognized. Accordingly, when a person naturalizes in Japan, Chinese nationality is considered to be automatically lost. This basic position has remained unchanged over time.

In the past (mainly from the 2000s to the early 2010s), there were cases where official certificates confirming renunciation of Chinese nationality were issued through Chinese public security authorities after Japanese naturalization. As a result, some applicants still believe such documents can be obtained.

However, in recent years, administrative practices in China have changed significantly. Chinese embassies, consulates, and public security authorities no longer issue individual certificates of nationality renunciation in practice.

Currently, the standard explanation is that Chinese nationality is automatically lost upon acquiring Japanese nationality, but documentation acceptable for submission in Japanese naturalization procedures is generally unavailable.

As a result, Japanese naturalization examinations for Chinese nationals are conducted on the premise that official renunciation certificates cannot be obtained. Japanese Legal Affairs Bureaus are fully aware of this situation, and the inability to submit such certificates does not normally disadvantage the applicant.

2. Applicants with South Korean Nationality

South Korea operates a nationality selection system under certain conditions, which creates important differences compared to Chinese nationality cases.

When a South Korean national naturalizes in Japan, renunciation of Korean nationality is generally required. However, under Korean law, nationality is not automatically lost, and formal procedures for renunciation or nationality selection must be completed after naturalization.

If these procedures are not properly completed after Japanese naturalization, the individual’s nationality status may remain legally unclear.

Additionally, mistakes in timing or procedure may affect Korean family registers, military service obligations, inheritance rights, and other legal matters. Therefore, it is essential to plan not only the naturalization application itself, but also the post-approval nationality procedures.

3. Applicants with Taiwanese Nationality

For Taiwanese nationals, nationality renunciation in naturalization cases is a highly practical and case-specific issue.

While renunciation is legally possible in Taiwan, careful coordination is required regarding the timing and documentation in relation to the Japanese naturalization process.

In practice, renunciation procedures in Taiwan must often proceed in accordance with the progress of the Japanese application, and mistakes in sequencing can affect the entire application.

Because Taiwan’s household registration and personal status systems are closely linked to nationality, renunciation may also lead to changes in legal status. Accordingly, it is important to consider not only whether renunciation is possible, but also the implications after naturalization.

4. Applicants with Vietnamese or Philippine Nationality

In Vietnam and the Philippines, renunciation of nationality is legally permitted. However, in practice, administrative procedures often take a very long time.

Approval from the home government and submission of multiple documents may be required, and in some cases the process can take several years. Coordinating the Japanese naturalization schedule with renunciation procedures is therefore critical.

In Japanese naturalization reviews, more importance is placed on whether renunciation procedures have already been initiated and concrete steps toward renunciation have been taken, rather than on whether renunciation has already been completed.

An applicant who has actively applied to and communicated with their home authorities is evaluated very differently from one who has taken no action at all.

5. Applicants with U.S. Nationality

In the United States, renunciation of nationality is clearly recognized under law, and U.S. citizens may formally renounce their nationality when naturalizing elsewhere.

However, U.S. renunciation procedures involve high government fees and strict interviews and documentation. In addition, tax-related considerations (such as the exit tax) may apply.

As a result, U.S. nationals must carefully evaluate whether and when to renounce their nationality after receiving Japanese naturalization approval.

If renunciation is being reconsidered due to financial or procedural burdens, it is essential to consult professionals in advance and confirm how Japanese authorities will assess the situation.

4. Naturalization Review When Renunciation of Nationality Has Not Yet Been Completed

1. Can You Apply for Japanese Naturalization Before Renouncing Your Nationality?

In many cases, it is possible to submit a Japanese naturalization application even if renunciation of nationality has not yet been completed.

However, in such cases, the review will confirm that renunciation is legally possible and that the applicant has both the intention and concrete actions toward renunciation.

2. Why “Good-Faith Efforts” Are Evaluated

Even for countries where renunciation is difficult, the evaluation differs significantly between applicants who have taken no action and those who are actively trying to proceed with the process.

How thoroughly the applicant has researched their home-country system and what steps they have actually taken become important factors in the decision-making process.

5. Risks of Denial Related to Renunciation of Nationality

In a Japanese naturalization application, the review is not limited to “which nationality you currently hold.” It also examines how you plan to organize your nationality status after acquiring Japanese nationality.

If your understanding or handling of nationality renunciation is insufficient, authorities may conclude that there are doubts about your suitability for naturalization, which can increase the risk of denial.

1. Cases More Likely to Lead to Denial

• You do not understand that renunciation of nationality is required and mistakenly believe “everything will be automatically resolved once I naturalize.”
• Although renunciation is legally possible under your home-country law, you have made no preparations or taken any concrete steps at all.
• You provide vague explanations or inaccurate statements about whether you hold nationality or about the status of your renunciation process.

A particularly risky attitude is: “I haven’t done anything yet, but I’ll think about it later.” Examiners assess how well the applicant understands nationality systems and whether they are acting responsibly.

Therefore, leaving matters unattended despite renunciation being possible, or changing your explanation repeatedly, may negatively affect credibility and lead to an unfavorable assessment.

2. Cases More Likely to Be Approved

• You understand your home-country nationality law and accurately grasp how it relates to Japan’s naturalization system.
• If renunciation is required, you have examined and prepared concrete procedures and a realistic schedule.
• If renunciation is difficult or impossible, you have organized the background and reasons and can explain them logically.

What matters is not only whether renunciation has already been completed, but also your good-faith attitude—understanding the system and responding sincerely.

Japan also recognizes that there are countries where renunciation is legally or practically difficult, and in such cases, flexible decisions based on individual circumstances may be made.

6. What to Do If You Are Concerned About Renouncing Your Nationality

Nationality renunciation rules vary significantly by country, and proceeding based on assumptions can increase risk.

1. First Priority: Confirm Your Home-Country Law

The first step is to confirm your home-country nationality law accurately.

Relying only on “information found online” or “a friend’s experience” can cause you to miss legal updates or country-specific conditions.

It is important to clarify whether nationality renunciation is:

• not permitted under the law at all
• formally permitted but extremely difficult in practice
• possible if certain conditions are met

2. Determine the Right Timing and Preparation

For countries where renunciation procedures take a long time, the timing of your Japanese naturalization application becomes critical.

In some cases, renunciation may be required promptly after naturalization approval; in others, it may be sufficient to complete it within a certain period.

Therefore, by clarifying in advance:

• how much preparation should be done before applying for naturalization
• what actions will be required after approval

3. Cases Where You Should Consult a Professional

In the following situations, consulting a professional can significantly reduce risk compared to proceeding on your own.

• Countries with complex renunciation rules or frequent legal/administrative changes
• Cases where it is unclear whether renunciation is possible
• Situations where you are concerned about consistency with past declarations or records

For Japanese naturalization, “correct understanding” and “consistent explanations” are essential. By organizing your strategy with a professional perspective, you can avoid unnecessary denial risks.

7. Conclusion: Country-Specific Understanding of Renunciation Is the Key to Successful Naturalization

Renunciation of nationality in Japanese naturalization is not handled identically for every country.

The key is to take realistic action based on accurate understanding of your home-country nationality system, not only Japan’s system.

Even if you feel anxious about renunciation, you do not need to worry excessively as long as you prepare properly and explain your situation consistently. Careful planning and judgment in advance are crucial to a successful Japanese naturalization application.

8.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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