Forced Heirship Claim Simulator | Did a Will or Gift Leave You Short of Your Reserved Portion?

Enter the estate value, the heirs involved, the claimant's relationship, and the amount they actually received, and this free simulator instantly calculates the forced heirship claim (Article 1046 of Japan's Civil Code).

The reserved portion (Article 1042 of Japan's Civil Code) is the minimum share of an estate guaranteed to statutory heirs other than siblings — that is, the spouse, children, and lineal ascendants (parents, grandparents, and so on). If a will or lifetime gift leaves an heir with less than that guaranteed share, the heir can bring a forced heirship claim (Article 1046) to recover the shortfall in cash.

Simulate from the estate value, the heirs involved, the claimant's relationship, and the amount actually received

Tips

  • A forced heirship claim is legally valid even if made verbally, but sending it by certified mail is recommended so there's a clear, documented start date for the statute of limitations.
  • The overall reserved portion is either one-half or one-third depending on who the heirs are, so check first whether lineal ascendants are the only heirs in your case.
  • If there's even one child, lineal ascendants aren't entitled to inherit, so entering a number of ascendants won't change the result.
  • A forced heirship claim isn't available to someone who renounced the inheritance, or who lost their inheritance rights through disqualification or disinheritance.

Frequently Asked Questions

Yes. It expires one year after the claimant learns both that the inheritance has begun and that a gift or bequest infringes their reserved portion. Even without that knowledge, it's barred once ten years have passed since the inheritance began (Article 1048). It's important to assert the claim promptly.

No. The reserved portion is guaranteed only to the spouse, children (or their substitute heirs), and lineal ascendants — siblings aren't entitled to one at all (Article 1042, Paragraph 1). Even if a will leaves a sibling-heir with nothing, they can't bring a forced heirship claim.

Gifts to heirs generally count if made within 10 years before the inheritance began, and gifts to non-heirs generally count if made within 1 year before (Article 1044). Gifts that both parties knew would infringe the reserved portion count regardless of when they were made.

Start by notifying the person who received more than their share. A verbal claim is valid, but certified mail is commonly used to establish a clear record for the statute of limitations. If direct discussion doesn't resolve it, the next step is family court mediation, followed by a district court lawsuit if that also fails.
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Side Note — Why the claim was renamed from a "reduction claim" to a "forced heirship claim"

Before Japan's Civil Code reform took effect in July 2019, this right was known as a "reduction claim." Under the old rules, when an heir whose reserved portion had been infringed brought a claim, the default outcome was "in-kind restitution" — the real estate or company shares that had been given away or bequeathed would end up co-owned between the claimant and the original recipient.

That co-ownership created real problems: selling the property, or exercising control over a company, now required the consent of every co-owner, which often caused serious trouble in business succession cases. So the 2019 reform consolidated the right into a purely monetary claim and renamed it the "forced heirship claim" to match.

Today the right is understood simply as a claim for cash, so the person on the receiving end doesn't have to give up real estate or company shares — they can resolve the claim by paying money instead. In exchange, the claimant no longer has a right to the property itself, but is guaranteed to be paid in cash.