In February 2017, a Seoul tenant signed a two-year jeonse contract and wired 95 million won to the landlord as a lump-sum deposit. No monthly rent bill arrived in the mailbox. When the contract ended in February 2019, the deposit did not come back either. What looked like Korean tradition was, in the courts, a loan that still had to be returned, and a set of registration rules that decided who got paid first.
Ninety-five million won on the table
That 95 million won figure is not an outlier invented for drama. It is the deposit amount recorded in litigation that reached the Supreme Court of Korea after the lease collapsed into auction and insurance payouts. For scale, the Housing Lease Protection Act treats tenants in the capital region with deposits up to 165 million won as small-amount lessees who can rank ahead of some secured creditors if they meet possession and registration rules.
Jeonse is often explained to foreigners as pay everything up front, get it back later. That description is accurate on cash flow, but it hides the pricing logic. The deposit is not prepaid rent for two years. Under the Civil Act, when the term ends the tenant returns the unit and the landlord must return the deposit. The Housing Lease Protection Act goes further: until the money is back, the lease relationship is deemed to continue even though the calendar term has expired.
So why are the numbers so large? The answer is not because Seoul is expensive, although it is. The answer lives in an interest-rate formula most tenants never see.
What jeonse is not
Start with what the law calls the deal. A jeonse contract is a housing lease with a refundable lump-sum deposit instead of monthly rent as the main payment. The tenant's obligation at move-out is to return the dwelling; the landlord's obligation is to return the deposit. If the landlord delays, the tenant can claim statutory default interest of 5 percent per year on the unpaid balance according to the Civil Act provisions summarized on easylaw.go.kr.
That legal frame matters because it breaks the myth that jeonse is simply rent paid in advance. Prepaid rent would shrink as you live in the unit. A jeonse deposit stays on the landlord's balance sheet until return day, behaving like a zero-coupon loan from tenant to landlord.
How common is the arrangement? KB Economic Research, citing the 2021 Housing Survey, notes that about 42.7 percent of national households rent, and that among those renters roughly 40.3 percent still use jeonse while 54.4 percent use deposit-plus-monthly semi-wolse contracts. Jeonse is not the majority anymore, but it remains a large enough share that its pricing rules move the whole market.
The conversion rate hidden in every listing
Real-estate platforms quote jeonse prices in won, not percent per year. Behind those won figures sits the jeonse-to-monthly conversion rate. The Korea Real Estate Board defines it from reported transactions as monthly rent times twelve divided by jeonse price minus monthly deposit, times 100.
Read that formula as a bond coupon. If the conversion rate is 5 percent, each 100 million won of jeonse capital pays about 420,000 won per month in housing service. KB Research uses exactly that arithmetic in a 2023 note on shifting jeonse demand. Change the rate, and the same apartment implies a different monthly rent equivalent without moving the furniture.
Researchers at the Korea Real Estate Board treat the rate as both the landlord's required yield and the tenant's opportunity cost when choosing jeonse instead of monthly rent. That is why listings feel like guesswork until you plug them into the formula.
How big is the typical rate? In a peer-reviewed 2024 study in the Journal of Real Estate Analysis, Kim Sang-bae estimates a national apartment conversion rate averaging 5.642 percent from January 2011 through August 2023, with observed values between 4.5 percent and 8.4 percent in the same sample. Those numbers come from the board's monthly national apartment series used in cointegration tests with market interest rates.
The national Housing Price Trend Survey that publishes conversion rates is designated official statistics under the Housing Act, with approval number 304004 on the open data portal. That designation matters because the conversion rate is a government-sanctioned market indicator, not a broker's guess.
When the central bank moved, deposits followed
If jeonse were only culture, deposits would track sentiment. Instead they track safe yields. Kim finds cointegration between the board's conversion rate and market interest rates such as the three-year treasury and mortgage lending rates, meaning shocks to rates and shocks to conversion rates drift back toward a long-run relationship even when the adjustment is asymmetric.
The chart shows quarterly averages of the Bank of Korea policy rate from 2019 through 2024, using the FRED series INTDSRKRM193N. The rate hugged 0.5 percent through 2019, collapsed to a 0.25 percent average in 2021 during the pandemic easing cycle, then climbed to a 2.0 percent average in 2023 as inflation fighting resumed. When safe yields fall, a landlord holding a jeonse deposit earns less on invested cash unless the lump sum itself rises or the tenant accepts a shift toward monthly rent.
KB Research describes that shift in plain language: after 2013, deposit-plus-monthly leases accounted for more than half of rental transactions, accelerating again when jeonse deposits spiked and some jeonse loan rates exceeded conversion rates in 2022. The lump-sum world did not vanish; it repriced.
Kim's structural break tests pin part of that repricing to measurable dates. National apartment conversion rates shifted again in August 2013 and October 2016 relative to treasury yields. Seoul can diverge from the national mean: KB Research cites Korea Real Estate Board data showing a 5.2 percent apartment conversion rate in Seoul in July 2023, compared with Kim's 5.642 percent long-run national average.
Borrowing the lump sum, gifting the yield
Most tenants do not keep hundreds of millions of won in a checking account. They borrow it. Banks extend jeonse loans; tenants pay interest while landlords invest the deposit and keep the spread. That is the everyday redistribution embedded in the system.
The tenant's bank interest is explicit. The landlord's return is implicit in the conversion rate on the same unit. When the three-year treasury yield sat near 2.97 percent in August 2026 according to FRED series IR3TIB01KRM156N, a national conversion rate above 5 percent still priced housing capital above safe government debt.
When a tenant with an existing jeonse contract asks to convert to monthly rent, the Housing Lease Protection Act caps the conversion rate at the Bank of Korea base rate plus 2.0 percentage points, according to KB Research's summary of the statute. KB's 2023 example uses a 3.5 percent base rate, implying a legal cap of base rate plus two points, or 5.5 percent in that example. Market averages can differ, but the cap anchors negotiations when a lease renews rather than when a brand-new monthly contract is written from scratch.
Scale the national mean conversion rate and you see why the lump sums feel like mortgage down payments. At 5.642 percent, a 500 million won jeonse deposit implies about 2.35 million won per month in rent equivalent. That is the number to repeat: the deposit is priced like a bond, not like a two-year rent total spread across months.
Getting the deposit back is a separate machine
Pricing explains the size of the check at move-in; a different mechanism decides whether the check comes back. To beat a new buyer or a foreclosing bank, a tenant needs opposing power and often a preferential repayment right. EasyLaw's English guide states that opposing power arises the day after delivery of the dwelling and completion of the resident registration, even if the lease is not registered on the title.
If the landlord will not pay on expiry, the tenant can apply for a court order for leasehold registration. EasyLaw notes that partial repayment still allows an order for the unpaid balance, and that foreign nationals can qualify through alien registration, citing Supreme Court decision 2015Da254507 handed down in 2019.
In the 95 million won case reported by Maeil Business Newspaper, the tenant moved out on 5 April 2019 while leasehold registration finished on 8 April 2019, after the landlord failed to pay at February expiry. Seoul Guarantee Insurance applied for the registration order in March 2019 and pursued the auction buyer. Lower courts sided with the insurer; the Supreme Court reversed them because possession ended before registration completed.
If a tenant of a house loses possession of a house, the opposing power will lapse when the possession is lost. If the leasehold registration is completed after the counterforce is lost, the extinguished counterforce will not be restored retroactively, but a new counterforce that is not identified with it will arise from the time the registration is completed.
The dwelling later sold at forced auction in July 2021 to a third-party buyer. Tenant B's 95 million won therefore sits at the intersection of bond math and procedural law: priced like a yield at signing, recoverable only if possession and registration align at exit.
The room on April fifth
After jeonse fraud scandals, KB Research notes public arguments that Korea should restrict jeonse altogether and push tenants toward monthly rent. Fraud is real; the easylaw guide now walks victims toward guarantee products and the Special Act on Support for Victims of Lease Fraud. Yet abolition alone does not erase landlord yield targets. When the board's conversion rate jumped relative to treasury yields in 2013 and again around 2016, according to Kim's structural break tests, the market was already repricing.
Registration law does not care how cleverly the deposit was priced if you leave too early.
On 5 April 2019, tenant B's apartment was empty three days before the registration timestamp caught up. The deposit was still 95 million won on paper. The policy rate, meanwhile, was beginning its own long walk from emergency lows toward 2023's 2 percent average. Jeonse looks like one wire transfer, but it is two linked machines: one that sets the lump sum using market interest, and one that decides whether you ever see it again.