❶ What Has Changed? A Comprehensive Breakdown.

Change ① The Residency Requirement Has Effectively Doubled

Until now, the continuous period of residence in Japan required for a naturalization application was "in principle, five (5) years or more."
As of April 1, 2026, this has been raised to "in principle, ten (10) years or more."
For those who have been preparing their application on the basis of a five-year residency, or whose application was already accepted under that standard, this is an extraordinarily significant development.
One critical point deserves emphasis here. The word "in principle" matters. The statutory text of the Nationality Act — which reads "having a domicile in Japan for five (5) or more consecutive years" — has not been amended. What has changed is the internal operational standard applied by the Minister of Justice when exercising discretionary authority to grant or deny naturalization. Accordingly, there remains the possibility that relaxed standards may apply to certain categories of applicants, including spouses of Japanese nationals, special permanent residents, and highly skilled professionals (details discussed below).

Change ② The Tax Compliance Verification Period Has Been Extended from "the Most Recent 1 Year" to "the Most Recent 5 Years"

Why Is Tax Compliance Subject to Examination?
A naturalization applicant is assessed on whether they demonstrate the intention and capacity to fulfill the obligations of Japanese citizenship. One of the most significant indicators of this is whether the applicant has been paying taxes in full and on time.
The examination covers national and local taxes, including income tax, inhabitant (residence) tax, and consumption tax (where applicable to business operators).
Comparison: Previous Standard vs. New Standard

	Previous Standard (until March 31, 2026)	New Standard (from April 1, 2026)
Verification Period	Most recent 1 year	Most recent 5 year
Volume of Required Documents	Relatively limited	Substantially increased
Impact of Past Arrears	Unlikely to be an issue if most recent year is clear	Full 5-year history subject to scrutiny

Who Is Most Likely to Be Affected?
The following applicants are advised to exercise particular caution:

• Those who experienced periods of unstable income due to career changes, self-employment, or business closure — There is a risk that inhabitant tax payments were delayed or that income tax filings were inadvertently missed during such periods.
• Freelancers, sole proprietors, and business owners — These individuals bear full personal responsibility for filing tax returns and remitting consumption tax, and every year within the five-year period must be verified as compliant.
• Those who worked multiple part-time or casual positions simultaneously — An obligation to file an independent tax return may have arisen without the applicant's awareness, and failure to do so would constitute an unfiled return.
• Those who had a period of unemployment or leave of absence within the past five years — Even in years with no income, a zero-income inhabitant tax declaration may be required. Failure to file may be treated as a missed declaration during the examination process.

What Happens If Arrears or Unfiled Returns Are Discovered?
The existence of any instance of late payment or an unfiled return within the past five years does not automatically result in denial. However, it will constitute a significant negative factor in the overall assessment.
It is strongly recommended that applicants, together with a qualified specialist, conduct a thorough review of their five-year tax history prior to filing, and address any issues through amended returns or retroactive payment before submitting the application.

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Change ③ The Social Insurance Verification Period Has Been Extended from "the Most Recent 1 Year" to "the Most Recent 2 Years"

Why Is Social Insurance Subject to Examination?
The payment status of social insurance premiums — including health insurance, employees' pension insurance, national health insurance, and national pension — is a critical benchmark for assessing whether an applicant has fulfilled their obligations as a member of Japanese society.
Comparison: Previous Standard vs. New Standard

	Previous Standard (until March 31, 2026)	New Standard (from April 1, 2026)
Verification Period	Most recent 1 yea	Most recent 2 years
Scope	Health insurance and pension	All categories of health insurance and pension

Who Requires Particular Attention?

• Those with unpaid National Pension premiums — It is extremely common for individuals who have left company employment to fail to complete the transition from Employees' Pension Insurance to the National Pension scheme, resulting in a gap in contributions.
• Employees whose employers were not enrolled in the social insurance system — While this is not the applicant's personal fault, it may nonetheless be treated as the applicant's issue during the examination. Where enrollment was legally required but did not occur, retroactive enrollment procedures may be necessary.
• Those with frequent short-term job changes — Gaps in health insurance coverage between resignation and re-employment are common. Failure to transition to voluntary continued coverage or National Health Insurance during such gaps may raise concerns.
• Those who transitioned from a student visa to a work visa — Where the applicant failed to apply for the Student Premium Exemption System during their studies, the National Pension records may reflect those years as periods of non-payment.

What Should Be Done If Gaps or Unpaid Premiums Are Discovered?
Rather than waiting until issues are identified during the examination process, applicants are strongly advised to proactively verify their pension records through the "Nenkin Teikibin" (Annual Pension Statement) or "Nenkin Net" online service, and to promptly complete any retroactive payment or enrollment procedures before filing.

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❷ Impact on Applicants Who Have Already Submitted — The Most Critical Notice

"I already submitted my application in March. This change doesn't apply to me." — Unfortunately, this assumption is incorrect.
The Ministry of Justice's official announcement is unambiguous:
"The new examination standards will apply to applicants who submitted their applications prior to April 1, 2026."
This means the relevant date is not the date on which the application was accepted, but rather the date on which the Minister of Justice renders a decision to grant or deny naturalization.
Accordingly, even if your application was formally accepted by a Legal Affairs Bureau in January, February, or March 2026, if the grant or denial decision is made on or after April 1, 2026, your application will be assessed under the new, more stringent standards.
What Can Applicants Under Review Expect?
The following outcomes are anticipated in practice:

Case ① Applicants Whose Period of Residence Clearly Falls Short of Ten Years

It is highly probable that the Legal Affairs Bureau will issue guidance recommending withdrawal of the application, advising that approval cannot be granted under the current circumstances.
In practice, it is common for authorities to encourage withdrawal rather than issue a formal denial, as a matter of consideration for the applicant. Should withdrawal occur, the applicant retains the full right to re-apply at a future date once all requirements — including residency, tax compliance, and social insurance — have been satisfied.

Case ② Applicants Whose Residency Is Close to Ten Years but Who Have Issues with Tax or Social Insurance Compliance

Even where the residency requirement is met, identified deficiencies in the five-year tax record or two-year social insurance record will render approval difficult. Whether the Bureau will afford an opportunity for supplementation of documentation or rectification, or will instead recommend withdrawal, will depend on the operational approach adopted by the relevant Legal Affairs Bureau. In either scenario, early consultation with a qualified specialist is strongly advised.

Case ③ Spouses of Japanese Nationals, Special Permanent Residents, Highly Skilled Professionals, and Other Eligible Categories

Applicants falling within the categories of simplified naturalization under Articles 6, 7, and 8 of the Nationality Act may be subject to relaxed application of the general ten-year requirement. However, the extent to which the current operational revisions affect simplified naturalization requirements must be confirmed directly with the relevant Legal Affairs Bureau on a case-by-case basis.

❸ How Is It Possible to Implement Such a Significant Change Without Amending the Law?

This is a perceptive and entirely legitimate question.
The statutory text of Article 5, Paragraph 1, Item 1 of the Nationality Act continues to read: "having a domicile in Japan for five (5) or more consecutive years." This language has not been altered.
What has been changed is the internal operational standard governing the exercise of ministerial discretionary authority — effectively, an internal administrative guideline. This revision was implemented by ministerial decision, without parliamentary deliberation and without a meaningful period of public notice.
There is an important legal consideration that applicants must be aware of: under the Administrative Appeal Act (行政不服審査法), decisions relating to the entry, departure, and naturalization of foreign nationals are expressly excluded from the scope of administrative appeal (審査請求). Naturalization is a matter entrusted to the broad discretionary authority of the Minister of Justice, and as such, there is no avenue under Japanese administrative law to contest a denial of naturalization through the administrative appeals process.
This is precisely why it is essential to prepare thoroughly and present the strongest possible application from the outset. There is no recourse after the fact. A single, well-prepared application is your most important opportunity.

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❹ Which Situation Applies to You?

 

Your Situation	Recommended Priority Action
Residency 5–9 years / Application not yet filed	Comprehensive review of application strategy required. Consider waiting until the 10-year threshold is reached, or assess eligibility for simplified naturalization.
Residency 5–9 years / Application currently under review	Contact your Legal Affairs Bureau promptly. Seek specialist advice before receiving any withdrawal guidance.
Residency 10+ years / Application not yet filed	Application may proceed under the new standards. However, a thorough review of the 5-year tax and 2-year social insurance record is essential before filing.
Residency 10+ years / Application currently under review	Residency requirement is satisfied. The extended verification periods for tax and social insurance compliance are the new critical focus.
Spouse of a Japanese National (married 3+ years)	Eligible for simplified naturalization. Confirm the scope of impact of this revision on your category.
Special Permanent Resident	Eligible for simplified naturalization. Same as above.
Child or Adoptive Child of a Japanese National	Eligible for simplified naturalization. Same as above.
Highly Skilled Professional / High-Point System Holder	Special provisions regarding residency period may apply. Individual assessment required.

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❺ Essential Self-Checks Before Filing Your Application

In addition to consulting a specialist, please review the following points independently.
✅ Tax Compliance Checklist (Past 5 Years)

• Have you filed an income tax return (or been subject to year-end tax adjustment by your employer) every year without exception?
• Have you received and paid your inhabitant tax assessment notice by the due date each year?
• In any year when you had no income, did you file a zero-income inhabitant tax declaration?
• If you are a business operator, have you filed and remitted consumption tax appropriately?
• Have you ever received a demand notice or pre-seizure notice from the tax authorities or your local municipality?

✅ Social Insurance Compliance Checklist (Past 2 Years)

• Were you continuously enrolled in Employees' Health Insurance and Employees' Pension Insurance throughout your period of company employment?
• Did any gap in insurance coverage arise at the time of resignation or change of employer?
• During any period of self-employment or freelance work, were you enrolled in National Health Insurance and the National Pension scheme, with premiums paid in full?
• Have you reviewed your pension record via the "Nenkin Teikibin" or "Nenkin Net" to confirm the absence of any gaps or unpaid periods?

During your period of study in Japan, did you apply for the Student Premium Exemption System? (If not, those years may be recorded as periods of non-payment in your pension record.)

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❻ Certified Administrative Procedures Legal Specialist Shinichi Narita Is Available to Assist You

As a Certified Administrative Procedures Legal Specialist (特定行政書士) with a dedicated focus on immigration and residency matters, I have supported numerous clients through the naturalization and residency application process.
The changes described on this page are not abstract policy matters — they have immediate and direct consequences for every foreign national considering naturalization in Japan. Each person's circumstances, however, are unique. Some applicants with ten or more years of residency will be well-positioned to proceed. Others with fewer than ten years may find that an alternative pathway is available.
What matters most is neither panic nor resignation — but an accurate understanding of your current situation, followed by a clear and well-considered strategy developed together with a qualified specialist.
My office offers assistance with the following:

• Assessment of residency period and compliance with the domicile requirement
• Detailed review of and advice regarding the five-year tax compliance record
• Verification of the two-year social insurance enrollment and payment record
• Development of a response strategy for applications currently under review
• Strategic advice on the timing and grounds for withdrawal and re-application
• Assessment of eligibility for simplified naturalization (spouses of Japanese nationals, special permanent residents, highly skilled professionals, and others)

 Begin with Free consultation by Free consultation mail form.
Please provide details of your current residency status, employment situation, and history of residence in Japan, and I will offer specific and practical advice tailored to your individual circumstances.
Consultations are available by Free consultation mail form. Consultations are conducted in both Japanese and English.
 
"Naturalization is one of the most significant legal decisions of your life. For that very reason, accurate information and the support of a trusted specialist are not optional — they are essential. I, Shinichi Narita, am committed to doing everything in my power to help you achieve your goal."
Shinichi Narita Certified Administrative Procedures Legal Specialist (特定行政書士) / Immigration Lawyer