Japanese Special Contribution Payment Inheritance Tax Simulator | How Much Tax on a Caregiving Claim?
Enter the total estate value, the composition of statutory heirs, and the special contribution payment amount to estimate the inheritance tax owed by the contributor (including the 20% surcharge) and the adjustment to the paying heirs' taxable estate.
When a relative who is not a statutory heir (typically a child's spouse) has provided unpaid care or other contributions to the decedent, they can claim monetary compensation from the heirs under Japan's special contribution payment system (Article 1050 of the Civil Code, introduced in a 2019 reform). For tax purposes, this payment is treated as a bequest from the decedent, so the contributor owes inheritance tax on it (Article 4, Paragraph 2 of the Inheritance Tax Act). Because the contributor is not a statutory heir, the 20% surcharge (Article 18 of the Inheritance Tax Act) always applies.
Run a Simulation from the Estate, Heir Composition, and the Contribution Amount
Tips
- A special contribution payment claim must be made within 6 months of learning of the decedent's death and the heirs, or within 1 year of the decedent's death (Article 1050, Paragraph 2 of the Civil Code). The right to claim expires once these deadlines pass.
- Because an heir who pays the special contribution payment can deduct that amount from their own taxable estate, the total tax burden across everyone involved stays roughly the same — the payment mainly shifts how the burden is split between the contributor and the heirs.
- Before the 2019 Civil Code reform, a child's spouse could provide years of devoted caregiving but had no way to claim anything, since only statutory heirs could benefit from the older "contribution share" system. The special contribution payment is a relatively new system created to correct this unfairness.
- Since the amount is set through negotiation between the parties, it's worth entering it into this tool once it's finalized to get a rough sense of the tax burden before filing.
Frequently Asked Questions
Side Note — What's the Difference Between "Contribution Share" and "Special Contribution Payment"?
Japanese inheritance practice has long recognized a "contribution share" (kiyobun) for heirs who made a special contribution to maintaining or increasing the decedent's assets. The catch was that only statutory heirs could claim it — so if a son's wife spent years caring for her parents-in-law, she herself, not being an heir, had no way to claim anything for it, a gap that was widely seen as unfair.
The special contribution payment, introduced in a Civil Code reform that took effect in July 2019, addresses this by giving relatives who are not statutory heirs a monetary claim of their own. It is available to blood relatives within the sixth degree, spouses, and relatives by marriage within the third degree — unmarried partners and friends are not eligible. The claim is limited to cases of unpaid care or similar labor that specifically contributed to maintaining or increasing the decedent's assets; simply living together or doing ordinary household chores usually isn't enough.
Another notable feature is how it's handled for tax purposes: the payment is treated as a "bequest," even though it's legally a claim under the Civil Code rather than something left by will. This fiction exists mainly to make sure the payment doesn't slip through the cracks of the inheritance tax system. As a result, the contributor occupies a somewhat unusual position — they're never counted toward the basic deduction's heir count, yet they're still subject to the same 20% surcharge that applies to any other third-party beneficiary.