The comprehensive real estate tax does not run “this published price, that much tax.” A deduction comes off, 60% is applied to build the taxable base, a rate table follows, the property tax already paid in July comes off again, a single-house household deducts more for age and holding period, and a rural surtax of 20% goes on at the end. Six steps.
1. The deductions are KRW 1.2bn and KRW 900m, and the gap between them is 180m where the tax is calculated. The 60% ratio is applied after the deduction, so the 300m does not carry across intact.
2. On the same home, having the relief and not having it is exactly 5.0 times. A published price of KRW 2bn at age 70 held 20 years comes to 532,800 won; the same home without the relief is 2,664,000 won (example).
3. July's property tax comes off here. 540,000 won in the example — the comprehensive tax sits on top of the property tax, but the overlapping part is given back (art. 9(3)).
Enter the combined published price and the taxpayer type and the six steps appear in order — plus age and holding period for a single-house household.
Houses only. The land tables (aggregate and separate) have their own rates and are not included. The tax-burden cap of 150% of the previous year (art. 10) is not applied — it needs last year's assessed figure, which this calculator does not have. The joint-ownership relief for a couple's single home, the exclusions for registered rental and employee housing, and the house-count exclusions for inherited and low-value provincial homes are also not applied. The property-tax offset assumes no reduction and no local rate adjustment. An estimate — check the November notice and Hometax for the real figure.
The numbers this calculator uses, and where they come from
The figures are split between the Act and its Enforcement Decree. The deductions and rates are in the Act; the 60% fair-value ratio is in the Decree — which means it can change without a vote in the National Assembly.
| Step | What applies | Source |
|---|---|---|
| Deduction | KRW 1.2bn for a single-house household, 900m otherwise | Act art. 8(1) |
| Fair-value ratio | 60% | Decree art. 2-4(1) |
| Rates | one table for two houses or fewer, one for three or more | Act art. 9(1) |
| Property tax offset | the property tax charged on the same houses | Act art. 9(3), Decree art. 4-3(1) |
| Age and holding | age 20%/30%/40% plus holding 20%/40%/50%, capped at 80% combined | Act art. 9(5)(6)(8) |
| Rural surtax | 20% of the comprehensive tax | Special Rural Development Tax Act |
The assessment date is 1 June. Whoever owns the property that day pays the whole year — the same date as the property tax.
How KRW 2bn becomes 532,800 won
The bar scale changes partway down because the top four lines are in billions and the bottom five are in won. On one scale the bottom five would be threads and show nothing. That gap is the point: in this example the tax is under 0.03% of the published price.
| Step | Amount | Note |
|---|---|---|
| Published price, combined | KRW 2bn | example |
| − single-house deduction | KRW 1.2bn | art. 8(1) |
| = taxable base | 480m | (2bn − 1.2bn) × 60% |
| Tax before offsets | 2,760,000 won | two houses or fewer |
| − property tax already paid | 540,000 won | art. 9(3) |
| − age and holding relief 80% | 1,776,000 won | art. 9(5) |
| Comprehensive real estate tax | 444,000 won | |
| + rural surtax 20% | 88,800 won | |
| Total | 532,800 won |
An 80% relief cuts the tax to exactly one fifth — from 2,220,000 won to 444,000 won. Without the age and holding lines the same home comes to 2,664,000 won, so those two lines are most of this notice. There is a separate piece on the age and holding relief.
KRW 1.2bn against 900m — not a 300m difference
The deduction comes off before the 60% ratio is applied. So a 300m gap in the deduction is 180m in the taxable base. Where the tax is worked out, that is the real difference, not 300m.
And a published price at or below the deduction leaves a base of zero (art. 8(1)). A single-house household owes exactly nothing up to KRW 1.2bn, and one won above it a base appears — 60% of that one won, so 0.6 won. Nothing lumpy happens at the threshold.
What this calculator does not do
The tax-burden cap (art. 10). Anything above 150% of the previous year's assessed tax is disregarded. That needs last year's figure, which this calculator does not have. In a year when published prices jump, this cap actually bites — if the notice comes in below the calculator, this is the likeliest reason.
The joint-ownership relief for a couple's single home. Each spouse can take KRW 900m, or one of them can be treated as the single-house household with the KRW 1.2bn deduction plus the age and holding relief. Which is better flips with age and holding period.
Exclusions from the total and from the house count. Registered rental and employee housing drop out of the aggregate; inherited homes and low-value provincial homes that meet the conditions drop out of the house count only — not out of the published-price total, which is an easy thing to get wrong.
Land. The aggregate and separate land tables have their own rates.
Property-tax reductions and local rate adjustments. The offset is computed as though neither exists.
Questions that remain
I paid property tax already. Why again?
They are different taxes. The property tax is local and everyone who owns property pays it. The comprehensive tax is national and only those above the deduction pay. Because the same home would be taxed twice, what was already paid as property tax comes off (art. 9(3)) — 540,000 won in the example above. There is a fuller comparison in property tax versus the comprehensive tax.
What is this about the fair-value ratio going up?
It is the multiplier that builds the taxable base. The Decree currently says 60%, and raising it has been floated repeatedly. It draws attention because a Decree can change without a vote in the National Assembly. The ratio multiplies the base directly, so a higher ratio raises the tax almost proportionally. Whether it has actually been amended has to be checked against the effective date — this piece uses the Decree effective 27 February 2026, which says 60%.
Where do I find the published price?
For apartments, the official published-price portal. It is the published price, not a market or transaction price, and if there is more than one home the total of all of them is where this calculation starts.
Who exactly is a single-house household?
One member of the household owning one home, alone. A home split between spouses does not qualify by default and moves across only by electing the joint-ownership relief. That one determination moves the deduction by 300m and decides whether the age and holding relief applies at all — check it first.
What if the notice differs from this?
Most likely one of the items listed above: the burden cap, an exclusion filing, the joint-ownership election, or a property-tax reduction. The notice is built from the ownership record the tax office holds, so start by checking that record.
Sources
Comprehensive Real Estate Holding Tax Act, effective 1 January 2026 (Act No. 21224 of 23 December 2025) — art. 8(1) base and deductions, art. 9(1) rate tables, art. 9(3) property-tax offset, art. 9(5)(6)(8) age and holding relief and the combined cap, art. 10 burden cap.
Enforcement Decree, effective 27 February 2026 (Presidential Decree No. 36132) — art. 2-4(1) the 60% fair-value ratio for houses, art. 4-3(1) the property-tax offset formula.
Local Tax Act, effective 1 January 2026 (Act No. 21308), art. 111(1)3(b) — the offset needs the standard property-tax rates for houses. Enforcement Decree art. 109(1)2 for the house fair-value ratio.
The articles were opened and read directly on the national statute portal. The rate tables were read at magnification band by band, and the running base at each band edge was checked to the won — that check caught a misreading in the last row of the three-house table.
Where to check further
Hometax, the simplified comprehensive real estate tax estimate. It runs on the ownership record the tax office holds.
The published-price portal. This is where the calculation starts.
The November notice. Payment runs from 1 to 15 December.
The September filing window for exclusions and the joint-ownership election. It opens once a year, and missing it is hard to undo.
