Mortgage Rules in Seoul and Gyeonggi: How LTV, DSR and Stress Rates Set the Ceiling
A mortgage limit in South Korea is not set by a single number. Collateral value filters it once, income filters it again, and a hypothetical interest rate filters it a third time. What remains after all three is the amount a borrower can actually draw. Two policy packages, announced in June and October 2025, tightened each of those filters in turn.
The design intent is explicit. The government sought to break the loop in which loan capacity expands automatically as house prices rise, and to build a buffer into the assessment so that limits do not surge when rates fall. This article takes that structure apart step by step. All won amounts are stated at their original value, with an approximate US dollar equivalent converted at KRW 1,397.7 per dollar, the Seoul market level reported on 19 August 2026.
Table of Contents
- Why the Rules Were Designed This Way
- Requirements and Structure by Lender Tier
- What the Data Shows on Rates and Limits
- How LTV, DSR and the Stress Rate Work in Sequence
- How It Differs From the Previous Approach
- Limitations and Blind Spots
- Frequently Asked Questions
- Summary
1. Why the Rules Were Designed This Way
When only a loan-to-value ratio applied, a rise in house prices lifted the borrowing ceiling with it, because the limit was simply a percentage of collateral value. The debt service ratio, which measures annual principal and interest against annual income, added a second axis.
The third axis is the stress interest rate. It builds the assumption of future rate increases into the assessment itself. In the measures announced on 15 October 2025, the financial authorities raised the floor for this add-on from 1.5 percentage points to 3.0 percentage points. A product priced at 4 per cent is therefore assessed as though it carried 7 per cent.
The perimeter widened in October 2025 to all twenty-five districts of Seoul and twelve areas in Gyeonggi Province, and three further Gyeonggi areas were added on 1 July 2026, bringing the total to fifteen. Incheon was not included.
An absolute cash ceiling sits on top. Under the June 2025 measures, home purchase mortgages in the Seoul metropolitan area and in regulated areas cannot exceed KRW 600 million (approx. USD 429,000), and the maximum term is 30 years. Ratio-based rules alone had not prevented total borrowing from growing on expensive properties.
2. Requirements and Structure by Lender Tier
Lender tiers in Korea are defined by the statute under which each institution is supervised, and that distinction carries through to the debt service ratio cap. Institutions governed by the Banking Act are held to 40 per cent; savings banks, mutual credit cooperatives, insurers and specialised credit finance companies are held to 50 per cent.
| Tier | Statutory basis | DSR cap | Structural characteristic |
|---|---|---|---|
| Policy mortgage | Korea Housing Finance Corporation, Housing and Urban Fund | Assessed separately | Income and price eligibility come first; the rate is fixed |
| Tier 1 | Banking Act | 40% | Linked to a benchmark index, with wide preferential margins |
| Tier 2 | Savings bank, mutual credit, insurance and credit finance statutes | 50% | More headroom on limits, but higher funding costs |
| Tier 3 | Lending Business Act | Assessed separately | Statutory ceiling of 20% a year; screening criteria not disclosed |
Figures are as of 19 August 2026. Read on the limit line alone, Tier 2 looks more generous, but its funding structure returns the difference through the interest rate. Chosun Biz reported that the lowest savings bank mortgage rates were in the 6 to 7 per cent range. Tier 2 lenders are also subject to aggregate household lending quotas, so a branch may stop taking applications even where headroom on the ratio remains.
3. What the Data Shows on Rates and Limits
The benchmark index is moving upward. COFIX (the Cost of Funds Index for Korean banks) on a new loan basis stood at 3.18 per cent for July 2026, published by the Korea Federation of Banks on 18 August 2026, the highest reading since January 2025. The outstanding balance basis was 3.00 per cent and the new outstanding balance basis 2.65 per cent.
| Basis | July 2026 | Change from June |
|---|---|---|
| New loan basis | 3.18% | +0.13%p |
| Outstanding balance basis | 3.00% | +0.06%p |
| New outstanding balance basis | 2.65% | +0.11%p |
That all three measures rose together matters. Borrowers on existing variable-rate loans are affected at their next reset, not only new applicants.
On the limit side, the ceiling steps down as the property price rises.
ource: 15 October 2025 housing market stabilisation measures, effective 16 October 2025*
Properties valued at KRW 1.5 billion (approx. USD 1.07 million) or less carry a KRW 600 million ceiling. Between KRW 1.5 billion and KRW 2.5 billion (approx. USD 1.79 million) the ceiling is KRW 400 million (approx. USD 286,000), and above KRW 2.5 billion it is KRW 200 million (approx. USD 143,000). The more valuable the collateral, the smaller the absolute sum available.
4. How LTV, DSR and the Stress Rate Work in Sequence
The three filters are not applied simultaneously. The loan-to-value ratio sets an initial ceiling, and the lower of that figure and the regional cash cap is taken. The debt service ratio is then calculated, using not the contractual rate but the rate plus the stress add-on. Whatever survives is the approved limit.
In regulated areas the loan-to-value ratio is 40 per cent for households that own no home and 70 per cent for first-time buyers. A single-property owner who commits to disposing of the existing home within six months is treated on the same basis as a non-owner. Households that keep an existing home and buy an additional one, and multiple-property owners, cannot obtain a purchase mortgage in a regulated area at all.
The stress add-on is weighted by rate type. It applies most heavily to fully variable products and most lightly to five-year reset products. Two applicants with identical income and identical collateral can therefore receive different approvals purely because of the rate type they select.
5. How It Differs From the Previous Approach
| Item | Before June 2025 | As of August 2026 |
|---|---|---|
| Limit calculation | Ratio-based | Ratio plus absolute cash ceiling |
| Assessment rate | Contractual rate | Contractual rate plus stress add-on |
| Maximum term | 40 to 50 year products available | 30 years in the capital region and regulated areas |
| Multiple-property owners | Conditional lending possible | No purchase mortgage in regulated areas |
| Residency | Applied to selected products | Move-in required within six months of drawdown |
The term restriction is the sharpest change. Extending the maturity to lower the monthly instalment, and thereby free up debt service capacity, no longer works in the capital region. What remains is clearing existing credit loans and overdraft lines before applying.
6. Limitations and Blind Spots
First, designation follows administrative boundaries, which creates sharp differences between neighbouring districts. Several Gyeonggi areas were designated at the district level rather than the city level, so conditions can differ within a single city. The perimeter is not fixed either. The Ministry of Land, Infrastructure and Transport (MOLIT, South Korea's housing and infrastructure ministry) added Dongtan-gu in Hwaseong, Giheung-gu in Yongin and the city of Guri on 30 June 2026, effective 1 July 2026, bringing the Gyeonggi total to fifteen areas.
Second, the additional headroom at Tier 2 lenders is rarely a practical remedy. Gaining ten percentage points of debt service capacity at a materially higher interest rate can leave total interest costs above the benefit.
Third, Tier 3 lenders sit outside these rules but do not constitute an alternative. The statutory interest ceiling is 20 per cent a year, and the Financial Services Commission's survey of the lending business industry put the average personal credit loan rate at 18.8 per cent as of end-December 2025. A secured loan on those terms still carries a heavy repayment burden.
Fourth, the maturity extension ban reaches back to borrowers who already hold loans. From 17 April 2026, multiple-property owners have in principle been unable to roll over apartment-secured loans in the capital region and regulated areas. Exceptions exist, including cases where a tenant is in occupation, but borrowers who do not qualify must prepare to repay or sell.
7. Frequently Asked Questions
Q. Incheon is not a regulated area. Does that mean borrowing there is unrestricted?
The 40 per cent loan-to-value cap does not apply. However, Incheon is part of the capital region, so the KRW 600 million ceiling on purchase mortgages and the stress rate add-on apply in full. In practice the binding constraint is usually income.
Q. Are policy mortgages exempt from these rules?
They are not. They carry their own income and property price eligibility tests, which narrows the pool of applicants. The Korea Housing Finance Corporation announced on 5 August 2026 that it would hold Bogeumjari Loan rates unchanged at 4.90 to 5.20 per cent a year on the Akkim-e product, with priority groups eligible for up to 1.0 percentage point of preferential reduction, giving 3.90 to 4.20 per cent.
Q. Does refinancing preserve the terms of an existing loan?
It does not. A new loan is assessed against the rules in force at the time of application. Prepayment fees also need to be counted. On KB Kookmin Bank's published schedule, property-secured loans drawn from 1 January 2026 carry a fee of 0.55 per cent on variable-rate loans and 0.75 per cent otherwise, and no fee applies once three years have passed from drawdown.
8. Summary
A mortgage limit is what remains after passing through three gates: collateral value, the regional cash ceiling and income. Being comfortable at two gates is of no help if the third blocks the application. Identifying which gate binds is the first step.
Where collateral value binds, the regional designation and first-time buyer eligibility are the items to check. Where income binds, the rate type and existing unsecured debt come first. In both cases, establishing whether a policy mortgage is available is the starting point.
Investment Disclaimer
This article is provided for information and analysis based on publicly available materials, and does not recommend the purchase, sale or holding of any financial product or real estate asset.
The figures and outlooks cited here reflect the sources available at the time of writing and may change thereafter. Regulations, tax rates, interest rates and eligibility rules apply differently depending on the effective date and on individual circumstances.
All investment decisions and any resulting gains or losses are the sole responsibility of the investor. Please consult a qualified financial, tax or real estate professional before acting on this information.
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