Mio doesn't guess — she does the arithmetic on the Japanese-language official tables. Enter your average monthly salary (a stand-in for your "standard remuneration") and how many months you paid Employees' Pension, and Mio estimates your gross lump-sum, the 20.42% tax taken at source, and what you'd actually keep — with and without reclaiming the tax. It is a rough estimate, not your exact refund. The real figure depends on your recorded standard-remuneration history and the current official schedule.
This tool models the Employees' Pension (厚生年金 / Kosei Nenkin) lump-sum, which is salary-based. The National Pension (国民年金 / Kokumin Nenkin) lump-sum uses a different fixed-amount table by months instead — it exists, but it isn't what's calculated here.
| What you actually keep (estimate) | Amount |
|---|
Leaving Japan is a moving target of deadlines — pension, tax, resident tax, closing accounts. The pension refund alone can be worth close to a million yen, and the 20.42% reclaim on top is real money that quietly expires. Get the sequence right before your final departure, because most of it can't be fixed after you've gone.
For the Employees' Pension, the official framework is roughly: gross lump-sum ≈ your average standard remuneration × a "payment rate" that grows with the number of contribution months, in 6-month bands, up to a cap. Mio uses this illustrative band table (the "final month April 2021 or later" schedule):
| Months paid | Illustrative multiplier (× average monthly salary) |
|---|---|
| 6 – 11 | 0.5 |
| 12 – 17 | 1.1 |
| 18 – 23 | 1.6 |
| 24 – 29 | 2.2 |
| 30 – 35 | 2.7 |
| 36 – 41 | 3.3 |
| 42 – 47 | 3.8 |
| 48 – 53 | 4.4 |
| 54 – 59 | 4.9 |
| 60+ (current CAP) | 5.5 |
These multipliers are illustrative and simplified from the published schedule. The count used is currently capped at 60 months — a recent pension-reform law raises this cap (toward 96 months / 8 years) with the effective date still to be set by cabinet order, so verify the current table before relying on any number. Under 6 months of contributions usually means no lump-sum at all. Then income tax of 20.42% (including the reconstruction surtax) is withheld from the gross at source.
Here's the part people miss. The lump-sum is taxed as retirement income, which gets a generous deduction — so the tax you actually owe is normally much less than the flat 20.42% that was withheld. To get the difference back you must appoint a tax representative (納税管理人 / nozei kanrinin) in Japan before you leave, then file a Japanese tax return after you've received the lump-sum. The representative files, receives the refund, and remits it to you. For many people this reclaims the large majority of the 20.42% — but only if you set it up in time.