Underwater Jeonse Risk Calculator
Check whether your deposit is safe against the property's value — in numbers. It computes the debt ratio (including senior mortgages) and simulates worst-case recovery and loss at auction. Thresholds are industry rules of thumb; always verify the property register and consult a professional before signing.
Deposit risk assessment
Debt ratio (senior + deposit) ÷ price
83.3%Risky
- Jeonse ratio (deposit ÷ price)
- 66.7%
- Deposit recovery rate
- 95.0%
- Est. recovery at auction
- 190,000,000 ₩
- Estimated loss
- 10,000,000 ₩
Metrics · basis
Jeonse ratio = my deposit ÷ market price
Debt ratio = (senior debt + my deposit) ÷ market price ← the key 'underwater' metric
Auction recovery = max(0, price × recovery rate − senior debt); loss = deposit − recovery
The 70/80/90% lines are industry/HUG rules of thumb, not law.
Auction recovery rate is a per-property assumption. Reference only — verify the register, HUG, and a professional.
What this tool does
An 'underwater jeonse' (깡통전세) is a lease where the deposit plus the landlord's senior debt approaches or exceeds the property's value — so if the home is auctioned, the tenant can't get the deposit back. This calculator turns that risk into numbers. It computes the jeonse ratio (your deposit ÷ market price) and the debt ratio ((senior mortgages + your deposit) ÷ market price), then simulates the worst case: how much you'd actually recover at a foreclosure auction, and how much you could lose. Everything runs in your browser — no data is sent anywhere.
Who uses this
- Deciding whether a specific jeonse or high-deposit wolse listing is financially safe
- Seeing how a landlord's existing mortgage (근저당) eats into what you'd recover
- Stress-testing a deposit against a lower auction price before you commit
- Foreigners assessing risk on their first Korean lease
- Checking if a home is near the ~80% deposit-to-value danger line before viewing
How to use (4 steps)
- 1Enter the property's market price — use real transaction data (실거래가), not the asking price.
- 2Enter the senior debt: mortgage amounts (근저당 설정액) from the property register's 을구 section, which are repaid before you at auction.
- 3Enter your deposit, then set an assumed auction recovery rate (default 80%) — lower it to be conservative.
- 4Read the debt ratio and risk band, plus the estimated recovery and loss if the home were auctioned.
How the risk is measured
Jeonse ratio = your deposit ÷ market price Debt ratio = (senior debt + your deposit) ÷ market price ← the key metric Worst-case (auction) simulation: Expected auction proceeds = market price × recovery rate You recover = max(0, proceeds − senior debt) (senior creditors are paid first) Estimated loss = max(0, your deposit − you recover) Rule-of-thumb bands (industry / HUG usage, NOT law): ≤ 70% relatively safe 70–80% caution 80–90% risky > 90% very risky (classic underwater jeonse)
Worked examples
Borderline case — ₩300M home
Market price ₩300M, senior mortgage ₩50M, your deposit ₩200M. Debt ratio = (50 + 200) ÷ 300 = 83% → 'risky'. At an 80% auction (₩240M), senior debt takes ₩50M first, leaving ₩190M — ₩10M short of your ₩200M deposit. You'd likely lose about ₩10M without deposit insurance.
Safe case — no senior debt
Market price ₩400M, no mortgage, your deposit ₩200M. Debt ratio = 50% → 'safe'. Even at an 80% auction (₩320M) you'd recover the full ₩200M. Still verify the register on balance-payment day — a new mortgage can appear between signing and move-in.
Frequently asked questions
What counts as 'senior debt'?
Anything repaid before your deposit at a foreclosure auction — most commonly the landlord's mortgage (근저당권) shown in the 을구 section of the property register, and unpaid taxes with an earlier statutory date. A deposit registered later ranks behind these.
Why does the auction recovery rate matter so much?
Foreclosed homes rarely sell for full market value. The winning bid (낙찰가율) varies widely by property and market — often 70–90% of appraised value. Because senior debt is paid from that reduced amount first, a lower recovery rate can wipe out a deposit that looked safe on the debt ratio alone. Simulate conservatively.
Is the 80% line an official rule?
No. The 70–80% deposit-to-value and ~90% debt-ratio lines are widely-used rules of thumb from HUG guidance and industry practice, not statutory limits. HUG/SGI deposit-insurance eligibility uses its own criteria that change over time — confirm current requirements directly with them.
The tool says 'safe' — am I protected?
It's only a screen based on the numbers you enter. It does not check the actual register, the landlord's taxes, trust registration (신탁), or whether move-in reports are allowed. Treat a 'safe' result as 'worth proceeding to full due diligence', not as a guarantee.
How do I lower my risk if the ratio is high?
Prefer wolse or ban-jeonse (smaller deposit), require the landlord to clear the mortgage before the balance payment, get HUG/SGI deposit-return insurance, and complete your move-in report + fixed date immediately. See the full jeonse-scam checklist linked below.
Cautions
- •Reference and educational tool, not legal, tax, or investment advice — verify the property register (등기부등본), HUG eligibility, and consult a licensed agent and lawyer before signing.
- •The 70/80/90% bands are industry rules of thumb, not law; your real risk depends on facts this tool cannot see.
- •Auction recovery rate is an assumption you set — real foreclosure outcomes vary widely by property.
- •Market price should come from actual transaction data, not the asking price, or the result is misleading.
- •A 'safe' score is a starting screen, not a guarantee — always complete full due diligence.
Last reviewed: 2026-07-02