Retirement allowance (taishokukin) tax in Japan — the deduction, the half-taxation, and the one form that stops a flat 20.42%

In many countries a lump-sum retirement payout is taxed as ordinary income and a big chunk vanishes. Japan does the opposite: it treats a retirement allowance (退職金, taishokukin) as its own category — retirement income (退職所得) — with two layers of relief that make it one of the most lightly taxed payments you'll ever receive. But that relief is not automatic: it hinges on one form. Mio doesn't guess — here are the numbers, read from the Japanese-language NTA sources, in plain English.

The two-layer relief on a lump sum

• 1. Retirement-income deduction (退職所得控除) — a tax-free slice based on your years of service:
  • first 20 years: ¥400,000 × each year
  • years beyond 20: ¥700,000 × each year
  • minimum ¥800,000; part-years are rounded up to a full year.
• 2. Half-taxation (½課税) — whatever is left after the deduction is then halved before tax rates apply (for a lump sum; short-service cases have exceptions).

Worked example — 38 years of service

Take someone with 38 years of service receiving a ¥20,000,000 lump sum. First, the deduction:

Because the ¥20.6M deduction exceeds the ¥20M payout, there is no taxable retirement income — effectively no income tax or resident tax on it. Now push the payout to ¥30,000,000 with the same service:

Received instead as a pension (split over years), the same money is taxed as public pension income (公的年金等) — aggregated with your other pension income, which can push your rate up or affect social-insurance charges. That's why, for most people, the lump sum tends to win — though very large payouts and iDeCo overlaps can change the answer.

Trap #1: no form → a flat 20.42% off the top

When you take the lump sum, everything above depends on one document: the "Application concerning receipt of retirement income" (退職所得の受給に関する申告書, the shinkokusho), handed to your employer before payment.

• Filed: the deduction and half-taxation are applied, so the correct (light) tax is withheld — often little or nothing.
• Not filed: a flat 20.42% is withheld on the gross payout, ignoring the deduction entirely. You can reclaim the overpayment by filing a tax return, but if you don't, you've simply overpaid.

Most employers hand you the form — but confirm you actually submitted it. For foreigners this matters twice over: if you're also leaving Japan, you may need to appoint a tax representative (nozei kanrinin) to handle any filing after you go. See: tax representative when leaving Japan →

Trap #2: iDeCo and your retirement allowance share one deduction

If you take your iDeCo as a lump sum too, it draws on the same retirement-income deduction as your company payout. Receive both in the same window and the deduction can overlap (counted once), leaving more of the total taxable. Whether you can stagger the years to use the deduction more than once depends on detailed rules that are frequently revised — so if you have both, check the current rule before choosing your timing. Related: NISA & iDeCo for foreign residents →

Which side are you on?

Mio's read

A Japanese retirement allowance is one of the few payments the tax system genuinely goes easy on — a large deduction, then only half taxed. The mistake isn't the receipt method; it's the paperwork. Calculate your deduction (¥400k/yr up to 20 years, ¥700k/yr after) and make sure the shinkokusho is filed — those two steps alone spare most people from overpaying. For very large payouts or an iDeCo overlap, run the numbers before you choose. This is a big-digits decision — when it's unclear, verify with the NTA or a tax professional.

Next: the full leaving-a-job money checklist → Leaving a job in Japan → · Filing when you leave Japan →