Singapore's TDSR caps all monthly debt repayments at 55% of gross income (as of 2026-06), while MSR imposes a stricter 30% ceiling on housing-loan instalments specifically for HDB flats and new Executive Condominiums. For HDB and EC buyers, both ratios must be satisfied simultaneously — MSR almost always binds first, setting the practical ceiling on how much you can borrow.
You found the flat, you have the downpayment, and yet the bank's loan quantum comes back lower than expected. In Singapore's residential lending framework, two interlocking ratio rules — the Total Debt Servicing Ratio (TDSR) and the Mortgage Servicing Ratio (MSR) — often explain the gap between what you want to borrow and what you are legally permitted to borrow. Understanding both rules is not optional paperwork: it is the single most important financial calculation you will do before signing an Option to Purchase.
What TDSR and MSR Are — and Why They Exist
The Total Debt Servicing Ratio (TDSR) was introduced by the Monetary Authority of Singapore (MAS) in June 2013 and tightened to its current 55% threshold in December 2021 (as of 2026-06). It applies to all property loans — private condominiums, landed houses, HDB resale flats, commercial properties — and to every lender regulated by MAS. The ratio measures total monthly debt obligations — the new mortgage repayment plus all existing debt servicing (car loans, personal loans, credit-card minimum payments, renovation loans, outstanding student loans, and any other property mortgages) — as a share of gross monthly income. If that combined figure exceeds 55%, the bank must decline or reduce the loan. MAS explains the TDSR framework in full detail on its regulatory explainer page.
MSR: The Additional Cap for HDB and EC Buyers
The Mortgage Servicing Ratio (MSR) is a second, narrower restriction layered on top of TDSR. It applies only to HDB flat purchases (both new BTO and resale) and to Executive Condominiums purchased directly from a developer. The MSR limit is 30% of gross monthly income (as of 2026-06), and it covers only the housing-loan repayment in question — not other debts. Because MSR is set at 30% while TDSR is set at 55%, and because TDSR encompasses all debts, an HDB or EC borrower with any existing debt obligations will almost always find MSR is the binding constraint. HDB's official financing guide sets out the MSR requirement alongside HDB concessionary loan eligibility.
Why These Ratios Matter Beyond Compliance
TDSR and MSR are not arbitrary bureaucratic hurdles — they are designed to prevent households from stretching into debt that becomes unserviceable when interest rates rise or incomes fall. The stress-test dimension of both rules reinforces this: banks do not size the loan against the promotional rate you were quoted. They apply a medium-term interest rate floor, which MAS has historically guided at 3.5% per annum for residential property loans, even when prevailing SORA-based mortgage rates are lower. This means the bank's calculation of your monthly repayment obligation is higher than your actual first-year bill, deliberately limiting borrowing capacity as a buffer against rate increases. Income from variable bonuses is typically discounted by 30%; rental income is haircut by 30% or more depending on the lender's internal policy. Commission-based earners and self-employed borrowers may see even heavier discounts on their declared income.
What Does It Mean?
Total Debt Servicing Ratio (TDSR)
Total Debt Servicing Ratio (TDSR) is a framework that limits total monthly debt repayments (including the new mortgage) to 55% of gross monthly income. This prevents over-leveraging and applies to all property loans in Singapore.
Mortgage Servicing Ratio (MSR)
Mortgage Servicing Ratio (MSR) is a stricter limit applied only to HDB flats and Executive Condominiums. MSR caps the monthly mortgage payment at 30% of gross monthly income, separate from the TDSR limit.
How Is It Calculated?
Total Debt Servicing Ratio (TDSR)
With $12,000 gross income and zero existing debt: max mortgage payment = $6,600/month.
Mortgage Servicing Ratio (MSR)
With $12,000 gross income: max payment = $3,600/month (applies to HDB and EC only).
Worked Example
With a gross monthly income of $12,000 and no existing debt:
For private property, your maximum monthly mortgage payment is $6,600. For HDB or EC, the stricter MSR limit of $3,600/month applies.
Why It Matters
TDSR determines the maximum property you can afford. Many buyers discover too late that their existing car loan or credit card debt significantly reduces their borrowing capacity.
Where to Find This on ShiokNest
- TDSR / MSR Affordability Calculator
Look for the tooltip icon next to this metric on ShiokNest for a quick reminder of its definition.
Official Sources
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The Core Rules at a Glance (as of 2026-06)
Before working through the numbers, a summary table of the two rules side by side:
- TDSR threshold: 55% of gross monthly income — all debt repayments combined.
- MSR threshold: 30% of gross monthly income — housing-loan repayment only; applies to HDB flats and new ECs.
- Stress rate: MAS-guided 3.5% p.a. floor used by banks to compute the monthly repayment figure for TDSR/MSR sizing (as of 2026-06). Actual disbursed rate is separate.
- Income haircuts: Variable components (bonus, commission) typically at 70% of 12-month average; rental income at 70%; self-employed income may require 2-year NOA average.
MAS's rules are codified in the MAS Guidelines on Responsible Lending for Property, which all banks and finance companies in Singapore must follow.
Worked Example — HDB Resale Flat Purchase
Assume a couple with a combined gross monthly income of S$10,000. They have one car loan with a monthly repayment of S$800 and a personal loan repayment of S$400, giving existing debts of S$1,200 per month. They intend to buy a 5-room resale HDB flat and take a bank loan.
Step 1 — MSR ceiling (30% × S$10,000): Maximum housing-loan repayment = S$3,000/month.
Step 2 — TDSR ceiling (55% × S$10,000): Maximum total debt = S$5,500/month. Subtract existing debts S$1,200 → maximum mortgage repayment under TDSR = S$4,300/month.
Step 3 — The binding constraint: MSR allows S$3,000; TDSR allows S$4,300. MSR is lower, so S$3,000/month is the cap.
Step 4 — Reverse-engineer the loan quantum: At a stressed rate of 3.5% p.a. over a 25-year tenure, a monthly repayment of S$3,000 corresponds to a loan of approximately S$624,000 (using a standard annuity formula). The couple's actual maximum bank loan for this HDB flat is roughly S$624,000, regardless of how much the flat costs. Use our TDSR calculator to run your own figures, or try the mortgage calculator to see how tenure and rate assumptions shift the repayment amount.
Step 5 — Private condo comparison: If the same couple were buying a private condominium (no MSR), the ceiling would be the TDSR-derived S$4,300/month. At the same stressed rate and tenure, that yields approximately S$895,000 in loan — 43% more. This illustrates concretely why private property buyers have materially higher borrowing capacity than HDB buyers with identical incomes and debt profiles.
CPF and Cash Interaction
The TDSR and MSR rules govern the bank-loan quantum only. CPF Ordinary Account (OA) savings can fund the downpayment and monthly instalments over and above the bank loan, but CPF usage for HDB flats is subject to the CPF Board's Withdrawal Limits and Valuation Limit framework, which is separate. A buyer may have more CPF than the bank loan allows but still cannot exceed the MSR/TDSR borrowing cap — the rules interact in parallel rather than in sequence.
How to Maximise Your Borrowing Capacity
- Clear high-repayment debts first. Each S$100 in monthly debt you eliminate opens approximately S$100 of additional mortgage capacity under TDSR. A car loan at S$1,000/month is worth roughly S$200,000 in additional loan quantum — often more valuable than a larger downpayment.
- Extend loan tenure strategically. Stretching from 20 to 30 years reduces the monthly repayment for the same loan amount, allowing you to borrow more within the TDSR/MSR cap. Be aware that LTV ratios also interact with tenure: loans above 30 years or extending past age 65 attract lower LTV limits under MAS rules.
- Add a co-borrower with income. Adding a spouse or family member with regular income to the mortgage application raises the gross monthly income denominator, proportionally lifting both the MSR ceiling (S$ figure) and the TDSR ceiling. Ensure the co-borrower has no undisclosed liabilities that would widen the debt side of the ratio.
- Restructure variable income documentation. If you earn commissions, bonuses, or rental income, ask your banker which averaging period and haircut they apply. Some banks accept a 24-month variable income average rather than 12 months, which can increase the qualifying income base.
- Use the TDSR calculator before shortlisting properties. Running your income and debt profile through the TDSR calculator and the affordability calculator before attending viewings prevents the frustration of falling in love with a unit the numbers will not support.
- Obtain an In-Principle Approval (IPA) early. Banks issue IPAs based on TDSR and MSR checks before you commit to a property. An IPA is not legally binding but gives you a reliable loan quantum, speeds up option exercise, and demonstrates to sellers that your financing is credible.
- Compare HDB concessionary loan vs bank loan. HDB concessionary loans (available only to eligible flat buyers) use a different MSR computation and charge a rate pegged at 0.1% above the CPF OA rate. They may allow a higher LTV (up to 80% vs 75% for bank loans on second property or lower in some cases) even if the monthly repayment cap is the same. Model both scenarios using the HDB grant calculator to compare total cost of ownership.
For Property Investors with Multiple Loans
- Sequence borrowing to protect TDSR headroom. The TDSR counts all outstanding mortgages. Buying a second investment property before clearing the first reduces the loan quantum available for either. Map your total debt servicing schedule before committing to additional purchases, and explore the cash-flow calculator to model rental income net of mortgage, maintenance, and tax.
- Rental income inclusion rules. MAS allows up to 70% of rental income from investment properties to be counted in gross income for TDSR purposes, but lenders may require a tenancy agreement, proof of receipt, and continuity evidence. Prospective rental that has not yet been contracted is generally excluded.
Frequently Asked Questions
What debts count towards TDSR?
Can I exceed the 55% TDSR limit?
This glossary article is auto-generated from ShiokNest's financial data and updated periodically. Rates and figures are current as of March 2026. Check official sources for the latest.