Onbid Public Auction (Gongmae) Bid & Profit Analysis

Onbid Public Auction (Gongmae) Bid & Profit Analysis helps compare Korea-related property income, yield, purchase cost, and holding-period scenarios in English.

Real estate scenario inputs

Enter Korea-related property, loan, lease, tax, or project assumptions. Results are simplified planning estimates.

Annual net income

₩4,920,000,000

Annual holding cost

₩30,000,000

Net annual cashflow

₩4,890,000,000

Cash yield estimate

978%

18 year horizon

This English page is a simplified estimate for Korea's public auction (gongmae), run by the Korea Asset Management Corporation (KAMCO) on Onbid under the National Tax Collection Act (2026). Each failed round lowers the minimum price by 10% of the first appraised price down to a 50% floor (Art. 87(2)); unlike a court auction there is no delivery order (indomyeongnyeong), so eviction requires a lawsuit; the payment deadline is 7 days from the sale decision, extendable to 30 days (Art. 84(5)). Confirm figures on the Onbid notice.

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Onbid Public Auction (Gongmae) Bid & Profit Analysis

This calculator estimates the profitability of Korea’s public auction (gongmae) held by the Korea Asset Management Corporation (KAMCO) on the Onbid platform. Starting from the reduced minimum price after failed rounds, it adds acquisition tax, registration cost, eviction-lawsuit cost, and holding cost, then shows net profit and returns (ROI / ROE) when you resell or rent the property.

A public auction looks similar to a court auction but rests on a different law. A court auction is run by the court under the Civil Execution Act, while a public auction is run by KAMCO on Onbid under the National Tax Collection Act, on delegation from the tax office or local government. Because of this, the reduction rate, eviction method, and payment deadline all differ, so a dedicated public-auction calculation is needed.

Korea-specific tool

This English page is based on Korean rules (National Tax Collection Act, Local Tax Act, Income Tax Act) as of 2026. It is a planning estimate and does not replace the official Onbid notice, appraisal report, tax filing, or legal advice.

The core: failed-round reduction (Art. 87)

The first step in public-auction investing is knowing the exact minimum public-auction price. Article 87(2) of the National Tax Collection Act provides that at each re-auction the minimum price is lowered by 10% of the first appraised price, in successive steps, down to a floor of 50% of the first appraised price; if it still fails to sell, a new appraised price is set. In short, each failed round drops the price by 10 percentage points of the appraisal, with 50% as the legal floor.

Minimum price by round (vs. appraised value)

  • • New listing (0 failed): 100% of appraisal
  • • 1st failed round: 90%
  • • 2nd failed round: 80%
  • • 3rd failed round: 70%
  • • 4th failed round: 60%
  • • 5th failed round: 50% (legal floor)
  • • After that: a new appraised price is set for re-auction, or the asset moves to a private contract

Unlike a court auction, which typically drops 20–30% per round, a public auction eases down by 10% each time. So a public auction reduces more slowly, but new rounds open frequently (often weekly) and move quickly. Move the failed-round slider and the by-round minimum-price table updates instantly, so you can see what percentage of the appraisal your current bid represents.

Key features

1. Automatic reduced-price calculation

Enter the appraised value (first minimum price) and the number of failed rounds, and the minimum price is computed under the National Tax Collection Act. The winning bid is pre-filled with the minimum price; edit it and the bid-to-appraisal ratio updates immediately.

2. Full acquisition-cost breakdown

Based on the winning bid, it applies acquisition tax (housing 1–3% progressive, 8–12% heavy rate for multi-home or regulated areas, 4% for non-housing), local education tax, special rural tax, registration license tax, court revenue stamp, and judicial-scrivener fee. First-home relief (up to 2 million KRW) and the 85㎡ exemption for special rural tax are reflected as well.

3. Eviction risk (the public-auction trap)

Unlike a court auction, a public auction has no delivery order (indomyeongnyeong). If the occupant refuses to leave, you must go through an eviction lawsuit (typically 6–12 months), which costs more time and money. The calculator takes eviction-lawsuit cost as a separate input, subtracts it from net profit, and also folds any assumed senior lease deposit (from a tenant with opposing power) into the required equity.

4. Deposit and payment-deadline guidance

The Onbid seized-asset auction bid deposit is 10% of the bid. Under Article 84(5) of the National Tax Collection Act, the payment deadline is 7 days from the sale decision in principle, extendable to 30 days if the tax office allows. The calculator shows the deposit and expected deadline based on the bid so you can plan the balance payment.

5. Resale / rental return simulation

For each exit strategy (sell, monthly rent, jeonse), it reflects capital gain, the long-term holding special deduction, capital gains tax, local income tax, and holding-period loan interest, property tax, and maintenance to derive net profit. Total ROI, equity ROE, annualized return, and rental yield are shown together so you can compare the leverage effect at a glance.

How to use

Step 1: Property type and appraised value

Pick the property type (apartment, officetel, commercial, land, etc.) and enter the appraised value (first minimum price) from the Onbid notice. Preset buttons enter 100M–1B KRW quickly.

Step 2: Adjust failed rounds

Set the failed-round slider (0–5) and the minimum price reduces automatically. The by-round table shows what percentage of the appraisal your bid is.

Step 3: Bid and costs

Enter the bid you intend to submit, plus eviction-lawsuit cost, assumed deposit, and repair cost. If you use a loan, set the loan ratio and interest rate to see your equity.

Step 4: Choose an exit strategy and calculate

Pick sell, monthly rent, or jeonse and a holding period, then run the analysis to see net profit, ROI / ROE / annualized return, and every cost from acquisition to sale on one screen.

Public auction vs. court auction

  • Law / operator: Public auction runs under the National Tax Collection Act via KAMCO (Onbid); court auction runs under the Civil Execution Act via the court.
  • Bidding: Public auction uses Onbid electronic (period) bidding online; court auction uses in-person date bidding at the court.
  • Reduction: Public auction drops 10% per round down to 50%; court auction typically drops 20–30% per round.
  • Eviction: A court auction offers a fast delivery order; a public auction has none, so you need an eviction lawsuit.
  • Payment: Public auction is 7 days (small) to 30 days from the sale decision; court auction is about a month after the sale-permission decision becomes final.

In short, a public auction is easy to join online and cycles through reduction rounds quickly, but you cannot solve eviction with a delivery order, so occupant-heavy properties demand extra caution. Public auctions shine on land, vacant lots, empty commercial units, or occupants without opposing power — cases where eviction difficulty is low.

Use cases

Winning a tax-arrears apartment at the 2nd failed round

An apartment appraised at 500M KRW that fails twice has a minimum price of 80% = 400M. Bid, say, 410M, add acquisition tax, eviction-lawsuit cost, and loan interest, and you immediately see the real net profit and equity return after an 18-month hold and resale.

A commercial unit with a senior tenant

When the winner must assume a senior tenant’s deposit, required equity rises sharply. Entering the assumed deposit shows how equity grows and how much the difference-payment option (Art. 84-2) can ease the cash burden.

Buying land after 5 failed rounds

Land has little eviction burden and suits beginners. For land reduced to 50% of appraisal after five rounds, you can pre-compute capital gains tax with the long-term holding deduction and the annualized return for a long hold.

Frequently asked questions

Q. How far below appraisal does an Onbid auction fall?

A. Under Article 87, each failed round lowers the price by 10% of the first appraised price, with a 50% floor. After five rounds it reaches half the appraisal; if it still fails, a new appraised price is set for another auction.

Q. Can I get a delivery order like a court auction?

A. No. A public auction has no delivery order. If the occupant does not leave voluntarily, you must file an eviction lawsuit, which usually takes 6–12 months and separate costs, so eviction risk must be built into your costs.

Q. When must I pay the balance?

A. Under Article 84(5), it is 7 days from the sale decision in principle, extendable to 30 days if the tax office allows. In practice, bids under 10M KRW often get 7 days and larger amounts up to 30 days.

Q. Are co-ownership share auctions safe?

A. For co-ownership shares, other co-owners hold a preemptive purchase right under Article 79. Even as the highest bidder, you can lose the sale if a co-owner exercises it, so treat share lots with care.

Q. Is the tax calculation exact?

A. It computes acquisition tax and capital gains tax under 2026 Local Tax Act / Income Tax Act rules, but results vary with your home count, heavy-tax status, and jurisdiction. Confirm final tax and rights analysis with a licensed tax accountant or judicial scrivener.

Tips and cautions

  • Rights analysis first: Check the distribution-demand deadline, move-in date, and fixed date to confirm whether any deposit must be assumed.
  • Budget for eviction: With no delivery order, subtract eviction-lawsuit cost and time from net profit before deciding.
  • Use difference payment: A mortgagee or senior tenant can pay only the difference after their distribution under Article 84-2, easing the cash burden.
  • Deposit forfeiture: If you miss the payment deadline, you forfeit the 10% bid deposit.
  • Read the Onbid notice: Review the property statement, appraisal report, and site survey on Onbid to back up your inputs.

Analyze your public-auction profit now

Enter the appraised value and failed rounds, and everything from the minimum price to net profit is computed automatically.

A public-auction-only analysis that reflects reduction, eviction risk, and tax — check your safety margin before you bid.