Pension Lump-Sum Calculator (脱退一時金)

About This Pension Lump-Sum Calculator

This calculator estimates the lump-sum withdrawal payment (dattai ichijikin) available to non-Japanese nationals who have contributed to the Japanese pension system and are leaving Japan permanently. It covers both the Employees Pension Insurance (kosei nenkin) and the National Pension (kokumin nenkin).

Select your pension type, enter your contribution details, and the calculator shows the gross lump-sum amount, applicable withholding tax, and net amount you receive. For kosei nenkin, it also provides a step-by-step tax reclaim guide.

The two pension types pay out very differently, and the calculator reflects that. Kosei Nenkin (employees' pension) is calculated from your salary history and is taxed at 20.42 percent at the source; Kokumin Nenkin (national pension) is a flat per-month amount based on the fiscal year and is paid out tax-free. If you contributed to both — common for people who were students, self-employed, or changed employment status — run the calculator once for each type.

The calculator also walks you through the optional but lucrative process of reclaiming the 20.42 percent withholding tax on Kosei Nenkin. This requires appointing a tax representative (nozeikanin) in Japan before you leave and mailing the original payment notice back to Japan after you receive it. The reclaim is worth doing: on a typical 3-year contribution history, the refund often exceeds 200,000 yen.

YenWise builds each tool for expats who need numbers they can explain to an employer, a tax accountant, or themselves. We document official sources, show intermediate steps where it matters, and flag every simplification. Use the calculator as a planning layer on top of primary documents (源泉徴収票, ねんきん定期便, brokerage statements), not as a substitute for them.

Who Should Use This Calculator

This tool is designed for foreign residents leaving Japan who have been enrolled in the Japanese pension system:

Note that eligibility requires between 6 months and 35 months (just under 3 years) of contributions in most cases, and the application must be filed within 2 years of leaving Japan. If you have contributed for 10 years or more (120 months), you are generally vested in the regular Japanese pension and are no longer eligible for the lump-sum withdrawal — in that case a different set of rules applies and this tool is not the right starting point.

If you are comparing job offers, planning a move within Japan, or preparing for year-end tax adjustment (年末調整) or final return (確定申告), run two or three scenarios side by side and save or screenshot the results for your records.

• •Expats who have contributed to kosei nenkin through their employer and are returning home
• •Self-employed individuals or students who paid into kokumin nenkin and are leaving Japan
• •Workers planning their departure timeline to maximize their lump-sum eligibility
• •Anyone cross-checking payslips, pension notices, or brokerage statements against official rules

How the Pension Lump-Sum Withdrawal Works

The kosei nenkin lump-sum is calculated using your Average Standard Monthly Remuneration, your number of contribution months, and a sliding-scale coefficient. The Standard Monthly Remuneration is capped at 650,000 yen (Grade 32). The lump-sum is classified as retirement income (taishoku shotoku) and is subject to 20.42% withholding tax at the time of payment.

The kokumin nenkin lump-sum is a flat amount per contributed month, determined by the fiscal year of your departure. Critically, the kokumin nenkin lump-sum is TAX EXEMPT. No withholding tax is deducted. You receive the full amount.

For kosei nenkin, the 20.42% withholding tax can be reclaimed by appointing a tax representative (nozeikanin) in Japan after departure. This is a 6-step process: obtain forms from your municipality, designate a representative, file a tax return within 5 years, and the representative receives the refund. Professional proxy services typically charge 15-20% of the refund as a fee.

The payment-rate coefficient for Kosei Nenkin rises with contribution length, from 0.5 for 6-11 months up to 5.5 for 60 months or more. A 2021 reform raised the maximum counted period from 36 to 60 months, which substantially increased refunds for longer-staying expats. If your last contribution month is April 2021 or later, the more generous 60-month calculation applies to you.

After you change an input, results update in the browser only — nothing is uploaded. Shareable URL parameters (where enabled) encode your scenario so you can reopen the same numbers later or send them to a spouse or accountant without creating an account.

Methodology & review

Lump-sum withdrawal (脱退一時金) amounts use post-April 2021 payment-rate bands for contribution months, separate Kosei vs Kokumin formulas, the Kosei salary cap, and the 20.42% withholding model for Kosei. Kokumin premiums follow fiscal-year tables. Eligibility warnings flag too-short or too-long contribution histories.

Each tool is reviewed when underlying rules change (for example Reiwa-year tax reforms, NISA contribution caps, or pension premium tables) and whenever we expand the long-form explanation. The “Last reviewed” date on the page is the date of the latest substantive content or formula review.

We distinguish three kinds of numbers: (1) exact under the stated statute, (2) statutory estimates with known caps, and (3) planning assumptions you control. Assumptions such as expected investment return or remaining working years are never hidden inside a black box.

• •Primary sources linked in the Sources section below
• •Browser-side calculation — inputs stay on your device
• •Editorial review date shown in the byline above the tool

Important Notes

To qualify for the lump-sum withdrawal, you must have paid pension premiums for at least 6 months and apply within 2 years of leaving Japan. The calculation uses official Japan Pension Service coefficients that are updated periodically.

The tax reclaim process for kosei nenkin requires a trusted person or professional service in Japan to act as your tax representative. If you do not reclaim the tax, the 20.42% withholding is final. Always verify current amounts with the Japan Pension Service before making financial decisions.

The tax reclaim process for Kosei Nenkin depends on having a trustworthy person or professional service in Japan. Many expats use a paid proxy (often a tax accountant or specialist firm), which typically charges 15 to 20 percent of the refunded tax as a fee. Even after the fee, most people recover substantially more than they would have by leaving the withholding in place, but weigh the trust and logistics carefully before committing.

Local city-tax nuances, special deductions (medical, housing loan credit details, foreign tax credits), and employer-specific social insurance rates can differ from simplified models. When your situation is complex, take the YenWise breakdown to a zeirishi or FP and adjust inputs using your actual forms.

Maximizing Your Pension Refund

Timing and paperwork matter enormously for this process. These points tend to make the biggest difference:

• •Designate your tax representative (nozeikanin) BEFORE you deregister your Japanese residence — doing it after you leave is much harder.
• •Keep every pension notice and payslip you ever receive; you will need historical contribution records to verify the calculation.
• •Mail the original lump-sum payment notice to Japan by tracked international courier — scans and photocopies are rejected by the tax office.
• •File the reclaim tax return within 5 years of leaving Japan; after that, the right to the refund expires.
• •If your home country has a totalization agreement with Japan, short contribution periods may count toward your home pension instead — check before applying for the lump-sum.
• •Bookmark the page with your scenario filled in, and re-run after any salary change, bonus, or rule update so your plan stays current.

Official Sources and Further Reading

• Japan Pension Service — Lump-Sum Withdrawal Payment
• Japan Pension Service — Japanese Pension System
• Japan Pension Service — Tax Representative