Why original-member redevelopment gains need separate periods
When a long-held old home becomes a new apartment, applying the original holding period to every part of the gain can misstate Korean capital gains tax.
The contributed property, additional cash paid and pre/post-approval value changes can have different deduction treatment.
Identical sale prices and total gains can therefore produce different tax results.
This calculator connects management-plan valuations, acquisition cost and settlement direction to show those differences.
It supports original owners and families comparing a pre-completion occupancy-right sale, a completed-home sale, a larger unit requiring payment and a smaller unit generating cash.
Use the results to collect association records and prepare a tax consultation.
Korea-specific 2026 rules · original membersVerified 2026-11-09 using the Decree effective 2026-10-01.
Tax estimates cover disposals from 2026-10-01 through 2026-12-31; other dates require a law-edition review.
Successor purchases, presale-right resales and compensation for owners giving up allocation are separate cases.
All financial inputs and outputs use KRW.
Records to obtain before entering figures
Valuation and acquisition evidence
E is the price of the existing building and associated land fixed by the management/disposal plan.
Use the amended price when the plan changes.
Do not substitute an asking price or automatically multiply it again by an association ratio.
Keep acquisition contracts and receipts so acquisition cost and deductible costs remain distinct.
Dates and cash direction
Verify acquisition, management/disposal approval, completion and disposal dates.
Cash paid to the association and cash received from it have opposite directions and different formulas.
Do not enter settlement cash again as an expense.
For a receipt event, obtain the ownership-transfer notice for the particular property.
Separate pre-approval deductible costs B from post-approval costs A.
Have uncertain common costs reviewed instead of entering them in both fields.
Family payments and relocation-loan interest are not automatically deductible.
Only enter amounts whose eligibility, attribution and absence of duplication have been checked.
Occupancy-right sale: before and after approval
Let K be acquisition cost and S the sale price.
The whole pre-approval gain is P=E−K−B.
With cash paid, Q=S−E−C−A is the post-approval gain and total gain is P+Q.
When there is no settlement, C is zero.
Retained share after a receipt
With cash received, Q=S−(E−C)−A and retained pre-approval gain R=P×(E−C)/E.
The main disposal gain is R+Q; the separate cash-event gain is H=P×C/E.
R+H=P preserves the original pre-approval gain without counting the disposed share twice.
Income Tax Act Article 95 limits the original-member occupancy-right deduction to the pre-approval land/building gain.
The post-approval right premium Q receives no long-term deduction.
The results show a 0% deduction for that segment, which does not mean the right itself is exempt.
Completed-home sale and the paid-cash portion
Decree Article 166(2)(1)
The paid portion is T=Q×C/(E+C); the old-property portion is U=P+Q×E/(E+C).
Their sum equals P+Q.
T uses approval-to-sale holding years, while U uses original-acquisition-to-sale years.
Neither a blanket completion-date start nor a blanket original-acquisition start reproduces the prescribed split.
For a completed home after cash receipt, total gain follows Article 166(2)(2).
Because Article 166(5) lists the paid case in paragraph (2)(1), this tool does not automatically extend its deduction periods to the receipt case.
Enter a professionally reviewed whole-gain deduction rate from 0–80% and confirm the review.
Without confirmation, gains remain visible while tax and transaction cash are pending.
Table 1, Table 2 and residence by segment
Korean 2026 long-term deduction tables and limits| Table | Minimum conditions and formula | Maximum |
|---|
| Table 1 | At least 3 full years; full holding years × 2% | 30% |
| Table 2 | At least 3 holding years and 2 verified residence years; 4% holding + 4% residence | 40%+40%=80% |
Table 2 eligibility and exemption eligibility are separate inputs.
For the paid portion, only new-home residence counts here; for the old-property portion, the tool adds verified pre-approval and post-completion residence.
An occupancy right uses verified pre-approval residence for its deduction.
Enter months; the residence percentage uses completed 12-month years.
Post-approval residence before demolition, household-member absence exceptions, complex residence histories and changes of use are outside the automatic scope.
Do not increase a residence input to approximate these exceptions.
NTS review decision 2022-0081, dated 2023-05-31, illustrates that long old-home residence does not establish Table 2 for the paid portion when new-home residence is below two years.
KRW 1.2 billion allocation and converted acquisition cost
High-value taxable fraction
For a main sale confirmed as exemption-qualified, multiply both gains and deductions by max(S−1,200,000,000,0)/S.
A price below the threshold produces zero only after eligibility is confirmed.
A confirmed fully taxable case uses a fraction of 1; unknown eligibility leaves tax pending.
Unknown original cost
Article 166(3) uses E×standard value at acquisition/standard value at approval.
Both standard values must be positive and refer to consistent property and ownership scope.
This converts acquisition cost; it does not turn the whole disposal into a standard-value assessment.
The segment table shows deductions before allocation; the summary shows the deduction after allocation.
Do not mix denominators between segments.
Partial shares, different land/building holding periods, mixed-use buildings and unregistered assets require separate review.
The opening confirmation limits automatic estimates to an ordinary sole-ownership home case.
Cash-receipt gain and advance filing
A receipt can represent a taxable partial transfer of the old property.
Its gain is H=C−(K+B)×C/E.
Verify cash-event exemption, Table 2 eligibility and residence separately from the later main sale.
Its high-value fraction is max(E−KRW 1.2 billion,0)/E, so a small cash payment is not automatically fully exempt.
Day after the ownership-transfer notice
The official NTS general guide confirms the day after the relevant notice and a filing/payment period within two months after that month-end.
A notice on 2026-10-31 gives a reference transfer date of 2026-11-01 and nominal deadline of 2027-01-31.
The nominal date excludes holiday adjustments and special extensions.
A missing notice leaves the date pending; a bank-payment date is not substituted automatically.
The NTS example with valuation KRW 1.5 billion, cost KRW 600 million and cash KRW 500 million illustrates a KRW 300 million gain.
Using the current KRW 1.2 billion threshold gives KRW 60 million of taxable gain.
The tool does not copy the source example’s 2020 KRW 900 million threshold, 32% deduction or historical progressive deductions into 2026 results.
Check whether a sale contract also disposes of a refund claim and whether the settlement is final.
Confirm with association records and the contract that the separate cash transfer belongs to you before estimating its tax.
If a right was sold first, an unconfirmed retained cash claim leaves cash tax and aggregation pending.
The ownership notice cannot precede the entered completion date.
Annual aggregation, tax rates and transaction cash
Ordinary national rates range from 6–45%, with an annual basic deduction up to KRW 2,500,000.
For cash receipt and main sale in the same year, aggregate income after long-term deductions and apply the remaining basic deduction once.
If the two entered remaining amounts differ, use the smaller amount once.
The standalone tax estimates must not be added.
Other same-year property disposals require a full annual review and leave estimates pending here.
Local income tax uses standard rates equivalent to one tenth of the national rates on the same base.
Amounts are floored below one won; payment-unit truncation, tax credits, reductions, local ordinance variations and penalties are excluded.
Multi-home surcharges and short-term rates are not automatically determined.
Confirm ordinary-rate treatment before using an estimate.
Transaction cash is S−A−tax−cash paid, or S−A−tax+cash received.
It is not investment profit after original cost, historical expenses and debt repayment, or a current bank balance.
A separate sale-net figure deducts post-approval costs and standalone main-sale tax only.
A cash event in another year leaves the combined transaction cash pending because that year’s rules have not been verified.
Worked examples of the segmented calculation
Completed home after payment: fully taxable, Table 1
Fictional dates: acquisition 2000-01-01, approval 2022-01-01, completion 2024-01-01, sale 2026-11-09.
Cost is KRW 300 million, valuation 800 million, payment 200 million, sale 1.5 billion, costs zero and remaining basic deduction 2.5 million.
Pre/post-approval gains of 500 million each become a 100 million paid portion and 900 million old-property portion.
Rates of 8% and 30% give a 278,000,000 deduction.
The base is 719,500,000, national tax 266,250,000, local tax 26,625,000 and total 292,875,000 KRW.
The incorrect blanket 30% calculation gives 282,711,000, a difference of 10,164,000.
Transaction cash including the payment is 1,007,125,000 KRW, which is distinct from investment profit.
High-value allocation or an occupancy right
With the same inputs, confirmed exemption eligibility and Table 1 retained, the taxable fraction is 20%, base 141,900,000 and total tax 37,647,500 KRW.
For a fully taxable right with expected completion 2027-01-01, only the 500 million pre-approval gain receives the 30% deduction.
Standalone right tax is 352,011,000 KRW.
Changing asset type changes a legal fact, so verify completion and the actual contract.
How to use the calculator and compare unit sizes
- Verify original-member status, ordinary rates and absence of other property disposals; select the asset.
- Enter acquisition, approval, completion and sale dates, plan valuation and settlement direction.
- Separate cost and pre/post expenses; verify exemption, Table 2 and residence months.
- For a receipt, confirm the notice and separate cash-event eligibility, then calculate.
- Enter each unit’s own sale price and settlement in scenarios A and B.
- Review segments, pending reasons and aggregation, then save the TXT consultation report.
Equal sale prices can distort a comparison of units with different market values.
Change price, settlement and eligibility one at a time to inspect sensitivity.
The incorrect-single-period comparison illustrates a calculation error, not guaranteed savings or a refund.
Do not assume unchanged law for 2027 or later, or count the construction period as residence.
Invalid inputs, unknown facts and loss segments
- Impossible or reversed dates, negative/nonfinite figures and out-of-range amounts do not produce an estimate.
- Cash received must be below valuation; converted cost requires positive standard values.
- Negative segments require a loss-offset and deduction-allocation review, even if total gain is positive.
- Unknown facts are not treated as satisfied. Editing inputs hides previous results.
Acquisition cost and valuation must refer to the same asset and ownership scope.
Mixing a whole-property value with an individual share changes both gain and settlement ratios.
Cases outside ordinary sole ownership need professional review even when the arithmetic is possible.
Organize membership evidence, annual-disposal facts and acquisition records before relying on a comparison.
Frequently asked questions
Who is an original member?
This tool covers an owner who contributed an existing property to an association and obtained an occupancy right.
A buyer who acquired the right from another member is outside the automatic scope.
Inheritance, gifts, ownership changes, multiple-unit allocations and commercial premises require separate review.
Does a long original holding period apply to every gain?
For an occupancy right, only the pre-approval property gain qualifies for the long-term deduction.
For a completed home with cash paid, the paid portion and old-property portion use different holding periods.
Do not assign the original acquisition date to the entire gain.
Is all cash received exempt for a single-home household?
Check the main disposal and cash event separately.
A qualifying high-value property can retain a taxable portion.
For the cash event, the high-value fraction uses the old-property valuation, rather than comparing the cash payment itself with KRW 1.2 billion.
Why can the paid portion fail Table 2 despite long residence in the old home?
The paid portion uses verified residence in the new home only.
If new-home residence is below two years, it uses Table 1 even when the original home was occupied for much longer.
A holding-period start date does not itself establish Table 2 eligibility.
Why enter a reviewed rate for a completed home after receiving cash?
Article 166(5) lists paragraph (2)(1), so the paid-case periods are not automatically extended to paragraph (2)(2).
The calculator computes the latter gain but requires a professionally reviewed deduction rate for residence attribution and other applicable facts.
Without confirmation, tax and transaction cash remain pending.
Can I add the two standalone tax estimates?
For events in the same year, aggregate income after long-term deductions and apply the remaining basic deduction once.
Adding standalone taxes can misstate progressive tax and deductions.
Other property disposals and loss offsets require review of the entire annual return.
Does the date cash reached my bank set the deadline?
The NTS general guide uses the day after the relevant ownership-transfer notice, followed by two months after that month-end.
The tool displays a nominal date.
Confirm special contracts, disputes, holidays, extensions and the actual applicable transfer date with the tax office.
Does pending mean no tax is due?
Pending means necessary facts or the applicable law edition have not been confirmed.
It does not establish exemption or remove a filing duty.
Save the review report, collect association records, residence evidence, the acquisition contract and deductible-cost receipts, then recalculate or consult a tax adviser.
Official sources and future checks
The National Law Information OPEN API was checked directly on 2026-11-09: Income Tax Act ID001565/MST280405, current effective date 2026-07-01 and relevant article edition 2026-01-01; Decree ID003956/MST290841, promulgated 2026-09-30 and effective 2026-10-01; Local Tax Act ID001649/MST282559, effective 2026-01-01.
Recheck deduction tables, rates, high-value thresholds and effective dates after amendments.
Before filing, recheck actual cost, amended valuation, final settlement, residence attribution, transfer timing, exemption, surcharge, annual aggregation, holidays/extensions and the reviewed deduction rate for a home after receipt.
Retain inputs and evidence together so future reviews can reconstruct the assumptions.