Inheritance Tax Minor & Disability Deduction Simulator | Estimate Deductions and Tax Owed
Enter the total estate value, the statutory heir composition, and the age of the qualifying heir to estimate the deduction and tax owed under Japan's inheritance tax minor deduction (100,000 yen x (18 - age)) and disability deduction (100,000 yen, or 200,000 yen for severe disability, x (85 - age)).
When an heir is a minor or has a disability, a set amount can be subtracted from that heir's calculated inheritance tax (the total inheritance tax apportioned according to their statutory share). Any portion of the deduction that can't be used up can also be subtracted from the tax owed by that heir's dependent-support obligor (in practice, this is often one of the other heirs).
Minor and Disability Deduction Amounts
| Minor deduction | 100,000 yen x (18 years old - age at the start of the inheritance) - applies to inheritances on or after April 1, 2022 |
|---|---|
| Disability deduction (general disability) | 100,000 yen x (85 years old - age at the start of the inheritance) |
| Disability deduction (severe disability, tokubetsu shōgaisha) | 200,000 yen x (85 years old - age at the start of the inheritance) |
| When the deduction can't be used up | The unused portion can be subtracted from the tax owed by the qualifying heir's dependent-support obligor (Inheritance Tax Act, Article 19-3 and Article 19-4) |
The age used to calculate the deduction is the heir's age in full years at the start of the inheritance (the date the deceased passed away). Consult a tax accountant or tax office for the exact eligibility requirements and deduction amount.
Simulate From the Estate Value, Heir Composition, and Qualifying Heir's Age
Tips
- The minor deduction equals 100,000 yen multiplied by the number of years remaining until age 18, rounding any fraction of a year up (for example, 17 years and 3 months counts as 1 year).
- The disability deduction applies to heirs whose disability grade has been certified, for example via a physical disability certificate or a rehabilitation (therapeutic) certificate. Whether the heir qualifies as severely disabled doubles the deduction amount, so checking the certificate's grade beforehand improves the accuracy of the estimate.
- The minor deduction and the disability deduction can both apply to the same heir if the requirements are met (for example, a 15-year-old child with a disability can receive both deductions).
- To subtract an unused deduction from a dependent-support obligor, that obligor must also be an heir in the same inheritance.
Frequently Asked Questions
Side Note — Why the Formula Is "100,000 Yen x Number of Years"
Both the minor deduction and the disability deduction are structured so the deduction amount depends on "the number of years remaining until the heir reaches adulthood or old age." This reflects the fact that minors and people with disabilities will keep needing living, education, or care expenses well into the future, so the system sets aside part of the estate to cover that. The longer the remaining years (in other words, the younger the heir is at the start of the inheritance), the larger the deduction — a design built directly around this idea of "costs that will be needed later."
The disability deduction's cutoff age of 85 is said to reflect average life expectancy in the system's design. The twofold difference in the deduction amount between general disability and severe disability (tokubetsu shōgaisha) similarly reflects the idea that the level of care needed, and the constraints on daily life, scale with the severity of the disability.
The mechanism allowing an unused deduction to be subtracted from a dependent-support obligor's tax acts as a relief measure, ensuring the system's underlying purpose — securing future living support — holds up even when the minor or disabled heir's own inheritance tax is small (or they inherit almost nothing). However, this relief is only available if the dependent-support obligor is also an heir in the same inheritance, which makes it an important consideration when planning how to divide the estate.