Consecutive Inheritance Tax Credit Simulator | Reduce Tax When Inheritance Occurs Within 10 Years
Enter the total estate value, the statutory heir composition, the tax paid on the first inheritance, its net asset value, and the years elapsed to estimate the consecutive inheritance tax credit (Japan's Inheritance Tax Act, Article 20) and the tax owed after the credit is applied. Free simulator.
When the current decedent themselves acquired property in a separate, earlier inheritance (the "first inheritance") and paid inheritance tax on it within 10 years before their own death, part of that earlier tax can be subtracted from the tax owed on the current inheritance. This is known as the Consecutive Inheritance Tax Credit (Inheritance Tax Act, Article 20), designed to ease the burden of the same property being taxed twice within a short span of time.
Consecutive Inheritance Tax Credit Formula
| A: Inheritance tax paid on the first inheritance | The inheritance tax the current decedent themselves was charged at the time of the first inheritance |
|---|---|
| B: Net asset value from the first inheritance | The net asset value (value of property minus liabilities) the current decedent acquired at the time of the first inheritance |
| C: Total taxable base of the current inheritance | The combined net asset value acquired by all heirs and beneficiaries in the current inheritance |
| D: Amount acquired by the qualifying heir | The net asset value acquired by this heir in the current inheritance (this tool assumes acquisition according to the statutory share) |
| E: Years elapsed | The number of years elapsed from the first inheritance to the current inheritance (fraction of a year rounded down; 10 years or more is ineligible) |
The number of years elapsed used in the calculation is the period from the start of the first inheritance to the start of the current inheritance, with any fraction of a year rounded down. Consult a tax accountant or tax office for the exact eligibility requirements and credit amount.
Simulate From the Estate Value, Heir Composition, and First-Inheritance Details
What Is the Consecutive Inheritance Tax Credit?
The consecutive inheritance tax credit (Japan's Inheritance Tax Act, Article 20) exists to soften the burden on a family when the same property gets taxed twice in a short span of time. If the person who just passed away (the decedent) had themselves inherited property in a separate, earlier inheritance (the "first inheritance") within the 10 years before their own death, and paid inheritance tax on it at that time, a portion of that earlier tax can now be subtracted from the tax owed on the current inheritance. This situation comes up most often when an elderly parent and grandparent, or an elderly parent and their own parent, pass away in close succession.
This simulator estimates the credit amount and the tax owed after the credit is applied, based on the total estate value, the statutory heir composition (whether there is a spouse and how many children), and the tax and net asset value from the first inheritance, along with the years elapsed since then. It is a simplified calculation that assumes the heirs are limited to a spouse and children, and that only one heir qualifies for the credit, so for an actual tax filing we recommend having a tax accountant review the figures.
Sources used in this calculation
Statutory figures such as tax and insurance rates come from the public bodies listed below. They change when the law is revised, so please also check the primary source before relying on the result for an important decision.
- Formula and eligibility for the successive-inheritance credit (Inheritance Tax Act art. 20) — National Tax Agency (国税庁) Effective from 1958-01 ／ Last checked 2026-09-18
- Japanese inheritance tax rate table and basic exemption amount — National Tax Agency (国税庁) Effective from 2015-01 ／ Last checked 2026-09-17
How to Use the Consecutive Inheritance Tax Credit Simulator
- Enter the total estate value Enter the combined taxable base acquired by all heirs and beneficiaries in the current inheritance.
- Choose the heir composition Select whether there is a spouse and how many children there are. This tool supports cases where the heirs are limited to a spouse and children.
- Choose the qualifying heir Select the one heir (either a child or the spouse) for whom the credit should be calculated.
- Enter the details of the first inheritance Enter the years elapsed, the inheritance tax paid at the first inheritance (A), and the net asset value acquired at that time (B).
- Check the results The qualifying heir's tax owed before and after the credit, along with the consecutive inheritance tax credit amount, will be displayed.
Tips for getting more out of it
- The consecutive inheritance tax credit only applies when the current inheritance occurs within 10 years of the first inheritance. Beyond 10 years, the credit amount becomes 0 yen.
- The years elapsed (E) is calculated by rounding any fraction of a year down. For example, 9 years and 11 months since the first inheritance is counted as "9 years."
- If the decedent did not actually pay inheritance tax at the first inheritance (tax A is 0 yen), there is nothing to credit, so the consecutive inheritance tax credit does not arise.
- This credit tends to come up when an elderly parent and child pass away in close succession (for example, a father dying shortly after his own father's death), so if this situation seems likely, it is worth consulting a tax accountant early.
When This Simulator Is Used
When inheritance passes from grandparent to parent, and then to you
If a parent passes away not long after inheriting from a grandparent, this lets you estimate the size of the credit ahead of time.
When planning ahead for elderly parents' estates
If one parent has just passed away and the other is elderly, you can estimate the likely tax burden and use it as a basis for considering lifetime gifts or other planning.
Researching figures before consulting a tax accountant
Getting a rough idea of the credit amount and tax owed before meeting with a tax accountant can make that conversation more productive.
Discussing how to divide the estate among heirs
Understanding how much the qualifying heir stands to benefit from the credit can inform discussions about how to divide the estate.
Inheritance Tax Glossary
- Consecutive inheritance tax credit (相次相続控除)
- A credit under Article 20 of Japan's Inheritance Tax Act that eases the near-double taxation that results when two inheritances occur within 10 years of each other.
- First inheritance (第一次相続)
- The earlier of the two inheritances, in which the current decedent themselves acquired property. The present inheritance is distinguished from it as the "current inheritance" (or "second inheritance").
- Net asset value (純資産価額)
- The value of property acquired through inheritance or bequest, minus liabilities and funeral expenses. It is used as the value of B in the credit formula.
- Statutory share (法定相続分)
- The share of the estate that each heir is entitled to under the Civil Code, used as a guideline for dividing property. This tool assumes the qualifying heir acquires property in this proportion.
- Inheritance Tax Act, Article 20 (相続税法20条)
- The statutory provision underlying the consecutive inheritance tax credit. It sets out the credit formula and the 10-year eligibility window.
- Years elapsed (経過年数)
- The number of years between the start of the first inheritance and the start of the current inheritance, with any fraction of a year rounded down. The credit rate is reduced in proportion to this figure, out of 10 years.
Frequently Asked Questions
Side Note — Why Does the "Within 10 Years" Limit Exist?
The consecutive inheritance tax credit was created to ease the burden on surviving family when the same property is taxed twice in quick succession. For example, if a grandfather dies and a father inherits and pays inheritance tax on the property, and then the father himself dies just a few years later and a child inherits the same (or part of the same) property, the property ends up being taxed almost twice within a short period.
The reason the credit rate decreases by 10 percentage points for each year elapsed is the idea that, as more time passes, the "back-to-back inheritance" nature of the situation fades, and the case comes to resemble an ordinary inheritance more closely. The 10-year limit is likewise set as a rough guideline for how long this kind of double-taxation relief is considered necessary.
The mechanism that caps the value of C ÷ (B − A) at 1 is an adjustment to prevent the credit from exceeding the tax actually paid at the first inheritance (A) in cases where the current estate (C) is larger than the net assets received at the first inheritance (B − A, roughly the after-tax amount actually received).