Co-residence House Inheritance Deduction Calculator

Check eligibility for Korea’s co-residence house inheritance deduction (Inheritance and Gift Tax Act Article 23-2): a 100% deduction of the inherited home value, capped at KRW 600 million, when a homeless lineal descendant who lived with the deceased for 10+ years (excluding years as a minor) in a continuous one-house household inherits that home. Nets out mortgage debt secured on the home, applies the 2026 progressive rates, and reflects the temporary two-house exceptions.

Tax scenario inputs

Enter Korea-related tax assumptions in KRW. The model uses a simplified effective-rate estimate.

Taxable transfer value

₩200,000,000

Estimated gross tax

₩20,000,000

Net tax after adjustment

₩20,000,000

After-tax amount

₩780,000,000

Effective rate

2.5%

This English page is a simplified Korea-related tax planning estimate. It does not reproduce official forms, progressive brackets, exemptions, local surtaxes, filing classifications, or eligibility decisions. Confirm current Korean rules before filing, paying, investing, or restructuring.

Related calculators

What is the co-residence house inheritance deduction?

Korea’s co-residence house inheritance deduction lets a homeless child who lived with a parent in the same home for many years deduct 100% of that home’s value from the inheritance tax base, up to KRW 600 million.
It is set out in Article 23-2 of the Inheritance and Gift Tax Act and is designed to protect the housing stability of one-house households and families who cared for elderly parents.

Because it applies on top of the spouse deduction, the lump-sum deduction, and the financial-asset deduction, it is a powerful way to cut inheritance tax once the conditions are met.
However, the three conditions (10 years of co-residence, 10 years as a one-house household, and inheritance by a homeless heir) are strict, and rules such as excluding years spent as a minor and temporary two-house exceptions make eligibility hard to judge.

Korea-based, 2026 rules. This calculator reflects the Inheritance and Gift Tax Act Article 23-2 (in force from 2026-01-02) and its Enforcement Decree Article 20-2 (in force from 2026-02-27). It is a reference estimate for Korean inheritance tax and does not replace professional filing advice.

The three conditions

All three conditions below must be satisfied.
If even one fails, no deduction is allowed, so each must be checked carefully.

1. Living together for 10+ continuous years

The deceased and the heir must have lived together in one home continuously for at least 10 years, counting back from the date the inheritance begins.
The single most common pitfall is that any period during which the heir was a minor (under 19) is excluded from the 10-year count.

  • • Even if you lived together since childhood, only co-residence after reaching adulthood counts.
  • • For example, 12 years together with 3 minor years leaves 9 net years, which fails the condition.
  • • Eligible heirs are limited to lineal descendants (children, grandchildren) and, under Civil Act Article 1003(2), the spouse of such a descendant who inherits by representation.

2. A one-house household for 10+ years

The deceased and the heir must have formed one household holding a single home (one-house household, high-value homes included) continuously for at least 10 years.
Periods in which the household owned no home at all are also counted toward the one-house period.

  • • Time spent renting with no owned home still counts as a one-house period.
  • • Even if the household temporarily held two homes, it is treated as one home if a statutory exception applies.
  • • A two-house period that does not qualify for an exception breaks continuity and can disqualify the deduction.

3. Inheritance by a homeless heir

On the date the inheritance begins, the heir must be homeless, or hold only that one home jointly with the deceased, and must have lived with the deceased and inherited that home.
An heir who owns another home besides the inherited one is not eligible.

  • • If the heir separately owns another home, the deduction is denied.
  • • A child who co-owned that home with the deceased is included.
  • • When a spouse inherits, the separate spouse inheritance deduction applies instead.

How the deduction is calculated

If all three conditions are met, 100% of the inherited home value is deducted, capped at KRW 600 million.
The base value includes the attached land but subtracts any debt of the deceased secured on that home and land as of the date the inheritance begins.

Deduction formula

Net home value = home value (incl. land) − secured debt
Deduction = min( net home value × 100% , KRW 600M )
  • • A large mortgage reduces the net home value and therefore the deduction.
  • • If the net value exceeds KRW 600 million, only KRW 600 million is deducted.
  • • If secured debt exceeds the home value, the net value is zero and no deduction applies.

Korean inheritance tax uses a five-tier progressive rate from 10% to 50% depending on the tax base.
Reducing the base by the deduction cuts tax at the marginal rate; deducting KRW 600 million at a 30% marginal rate saves roughly KRW 180 million.

How to use this calculator

Step 1. Enter the inherited home

Enter the home’s appraised value and any debt of the deceased secured on it, in units of 10,000 won.
Leave the debt at zero if there is no mortgage.

Step 2. Enter the co-residence details

Enter the total continuous years lived together, the years the heir was a minor, and any unavoidable time apart.
The calculator subtracts the minor and absence years to find the net qualifying period.

Step 3. Enter the one-house history

Enter the years the household kept a single home, and pick the exception if it ever held two homes temporarily.
Include renting periods with no owned home in the one-house years.

Step 4. Confirm heir status and judge

Choose whether the heir is a lineal descendant and homeless at the start of the inheritance, then press Judge.
The pass/fail of each condition, the deduction amount, and the tax saving appear at once.

Exceptions people often miss

Temporary two homes still treated as one

Enforcement Decree Article 20-2(1) lists eight cases where a temporary second home is still treated as a one-house household.
If any applies, that period still counts as a one-house period.

  • • The deceased bought another home, creating a temporary two-house situation (former home sold within 2 years).
  • • The heir married someone who owned a home (that spouse’s home sold within 5 years of marriage).
  • • Households merged to care for a lineal ascendant aged 60+ (the other home sold within 5 years of merging).
  • • The deceased married someone who owned a home (that spouse’s home sold within 5 years).
  • • The deceased owned a registered cultural-heritage home, a farm-leaving home, or a farm-return home.
  • • A minority share in a home co-owned through a third party’s prior inheritance.

Unavoidable time apart

If you lived apart briefly for unavoidable reasons such as military conscription, schooling, work circumstances, or medical care, you are still treated as living together continuously.
However, that time apart is not added to the 10-year period, so continuity holds but the qualifying period shrinks.

For example, two years apart for military service are treated as an absence and excluded from the 10-year count.
Enter those years in the unavoidable-absence field and the calculator reflects them automatically.

Frequently asked questions

Q. Does a spouse who inherits get this deduction?

A. No. Eligible heirs are limited to lineal descendants and, by representation, the spouse of such a descendant.
When a spouse inherits, the separate spouse inheritance deduction (at least KRW 500 million) applies instead.

Q. Does living together since early childhood help more?

A. No, because years spent as a minor (under 19) are excluded from the 10-year count.
Only co-residence with the parent after reaching adulthood, totaling 10+ years, qualifies.

Q. We only ever rented — do we meet the one-house condition?

A. Yes. Periods with no owned home are counted toward the one-house period.
Homeless years plus one-house years together must reach 10+ years.

Q. Can it be combined with other deductions?

A. Yes. It applies separately on top of the lump-sum, spouse, and financial-asset deductions.
Once the conditions are met, up to KRW 600 million is deducted in addition to the others.

Q. Can I file directly from this result?

A. This is a reference judgment tool.
Actual filing requires evidence of co-residence, household composition, and home ownership history, so consult a tax professional.

Tips and cautions

  • Always subtract minor years: the net period after removing minor years must reach 10+ years.
  • Resident registration alone is not enough: actual co-residence matters and is often disputed, so keep proof of real residence.
  • Status at the start of inheritance is key: condition 3 is judged as of that date, so clearing any other owned home beforehand can help.
  • Confirm secured debt accurately: the base is the net value after subtracting debt, so reflect the remaining loan precisely.
  • Remember the KRW 600M cap: however large the net value, the deduction is capped at KRW 600 million.

Check your co-residence house deduction now

Verify the 10-year co-residence, 10-year one-house, and homeless-heir conditions one by one, and estimate the deduction and tax saving.

Based on the Inheritance and Gift Tax Act Article 23-2 and Enforcement Decree Article 20-2, 2026 rules.