TDSR and MSR: Exam-Ready Worked Examples

TL;DR: The Total Debt Servicing Ratio (TDSR) limits a borrower's monthly debt obligations to 60% of their gross monthly income, with variable components like commissions and bonuses subject to a mandatory 30% haircut. For RES exam candidates, mastering the distinction between fixed and variable income is the first step toward passing Paper 2.

In the RES exam, questions often feature a 'Property Agent' or 'Sales Manager' with a mix of basic salary and commission. According to MAS Guidelines, only 70% of variable income can be counted toward the TDSR calculation.

Worked Example: Buyer: Mr. Tan, a Singapore Citizen. Fixed Salary: $6,000 Average Monthly Commission: $4,000

Step 1: Calculate Eligible Income Fixed Income: $6,000 Variable Income ($4,000 x 70%): $2,800 Total Eligible Monthly Income: $8,800

Step 2: Apply 60% TDSR Limit $8,800 x 0.60 = $5,280

Mr. Tan’s total monthly debt (including the new mortgage, car loans, and credit cards) cannot exceed $5,280. For RES exam candidates, this topic falls under Marketing, CPF & Finance in Paper 2. You can practice questions on this in the Prepare app.

To calculate TDSR for the RES exam, first apply a 30% haircut to all variable income components before multiplying the total by the 60% threshold. This ensures the borrower has a sufficient financial buffer against income volatility, a key principle regulated by the Monetary Authority of Singapore (MAS).

When calculating the monthly installment for TDSR in an exam scenario, you must use the medium-term stress test interest rate rather than the actual market rate. As of 2026, the stress test rate for residential properties remains at 4% per annum.

Worked Example: Scenario: A $1.2M condo purchased by a Singapore Citizen (First Property). Loan Amount: $900,000 (75% LTV) Loan Tenure: 30 years Stress Test Rate: 4%

Step-by-Step Calculation: Using a standard mortgage formula (or provided tables in the exam), a $900,000 loan at 4% over 30 years results in a monthly installment of approximately $4,297.

The Trap: Students often use the current market rate (e.g., 3.2%) provided in the preamble. Always check if the question asks for 'eligibility' or 'actual payment.' For eligibility, the 4% stress test is mandatory for residential properties, while 5% is used for non-residential properties.

Property Type	Stress Test Rate (2026)	Regulatory Body
Residential (Private/HDB)	4.0%	MAS
Non-Residential (Commercial)	5.0%	MAS
HDB Loan (Concessionary)	3.0%	HDB

The residential stress test rate of 4% is a regulatory requirement used to determine the maximum loan amount a borrower can qualify for under TDSR rules. This higher-than-market rate ensures that homeowners can still afford their mortgage payments if interest rates rise significantly in the future.

The Mortgage Servicing Ratio (MSR) is a stricter requirement that applies specifically to HDB flats and new Executive Condominiums (ECs). Unlike TDSR, which looks at all debts, MSR focuses solely on the mortgage payment, capping it at 30% of the borrower's gross monthly income.

Worked Example: Buyer: A couple (Singapore Citizens) buying a 5-room HDB resale flat. Combined Fixed Income: $10,000 Existing Debts: $1,200 (Car loan) — Note: Ignore this for MSR, but keep it for TDSR!

Step 1: Apply 30% MSR Limit $10,000 x 0.30 = $3,000

This means their HDB loan monthly installment cannot exceed $3,000. Even if their TDSR allows for a higher payment (60% of $10,000 = $6,000), the MSR acts as the primary bottleneck for HDB and EC purchases.

Exam Tip: If a question asks for the 'Maximum Loan' for an HDB flat, you must calculate both MSR and TDSR. The lower of the two figures will determine the final loan amount. This is a common point of failure for many of the candidates who contribute to the roughly 45% pass rate cited in the CEA 2025 Annual Report.

For HDB and EC purchases, the Mortgage Servicing Ratio (MSR) limits the monthly mortgage installment to 30% of the household's gross monthly income. This calculation must be performed independently of the TDSR, and the borrower must satisfy both ratios to qualify for a housing loan in Singapore.

Understanding the overlap between TDSR and MSR is crucial for Paper 2. The RES exam frequently tests your ability to identify which rule applies to specific property types.

Feature	TDSR (Total Debt Servicing Ratio)	MSR (Mortgage Servicing Ratio)
Limit	60% of Gross Monthly Income	30% of Gross Monthly Income
Property Types	All Properties (Private, HDB, Commercial)	HDB Flats & New ECs only
Debts Included	All (Mortgages, Cars, Credit Cards, Personal)	Only the Mortgage being applied for
Variable Income	30% Haircut Applied	30% Haircut Applied
Stress Test	4% (Resi) / 5% (Non-Resi)	4% (For Bank Loans)

As of 2026, there are over 33,000 registered property agents in Singapore who must navigate these regulations daily. For RES exam candidates, this topic falls under Marketing, CPF & Finance in Paper 2. You can practice questions on this in the Prepare app.

TDSR applies to all property loans and considers all debt obligations, whereas MSR is specific to HDB and EC purchases and only considers the mortgage payment. Both ratios utilize a 30% haircut on variable income and a 4% stress test rate to ensure robust financial planning for buyers.

In the RES exam, a common scenario involves a buyer who appears wealthy but has significant monthly liabilities. TDSR is 'Total' for a reason—you must subtract existing monthly debt obligations from the 60% limit to find the available room for a mortgage.

Worked Example: Buyer: $12,000 monthly income (Fixed). Existing Car Loan: $1,500/month. Minimum Credit Card Payments: $500/month.

Step 1: Calculate Total TDSR Room $12,000 x 0.60 = $7,200

Step 2: Subtract Existing Liabilities $7,200 - $1,500 (Car) - $500 (Credit Card) = $5,200

The Trap: Forgetting to include minimum credit card payments or personal loans. The exam might list 'Total Credit Card Balance: $10,000.' Unless stated otherwise, the monthly liability for TDSR is typically 3% of the outstanding balance or the minimum payment amount specified in the question.

To accurately calculate a borrower's TDSR, you must subtract all recurring monthly debt obligations, such as car loans, study loans, and credit card minimum payments, from 60% of their gross monthly income. The remaining balance represents the maximum monthly installment allowed for any new property mortgage.

Q: Does TDSR apply if I am not taking a loan? No. TDSR and MSR are frameworks used by financial institutions to regulate lending. If a client is paying fully in cash, these ratios are irrelevant. However, they must still pay the relevant Buyer’s Stamp Duty (BSD).

Q: What interest rate do I use for HDB Concessionary Loans? For HDB concessionary loans, the interest rate is pegged at 0.1% above the current CPF Ordinary Account (OA) rate. As of 2026, this is 2.6%. The stress test for HDB loans specifically uses 3.0%.

Q: How is the loan tenure determined for joint borrowers? In the RES exam, you may see the 'Income Weighted Average Age' (IWAA) used to determine tenure. This is a common calculation in Paper 2.

Q: Are bonuses considered variable income? Yes. Any non-guaranteed income, including bonuses and commissions, must have a 30% haircut applied before being factored into the TDSR or MSR.

Candidates should consult the Estate Agents Act (Cap. 95A) and HDB Resale Procedures for the most current regulatory context. The RES exam registration fee is S$408.55 in 2026, making it vital to pass on your first attempt by mastering these calculations.

This final example combines TDSR, LTV, and Stamp Duties—a classic 15-mark structured question pattern.

Scenario: Mr. Lim (SC) wants to buy a second residential property priced at $1,500,000. Income: $15,000 (Fixed). Existing Home Loan: $3,000/month.

Step 1: Calculate TDSR Limit $15,000 x 0.60 = $9,000. Available for new loan: $9,000 - $3,000 = $6,000/month.

Step 2: Determine LTV (Loan-to-Value) Since this is his second housing loan, the max LTV is 45% (if the tenure exceeds 30 years or age 65) or 25% (if both conditions are met). Assuming standard 25-year tenure: Max Loan = $1,500,000 x 45% = $675,000.

Step 3: Calculate Cash/CPF Required Price: $1,500,000 Loan: $675,000 Shortfall: $825,000 Plus ABSD (20% for SC 2nd property in 2026): $300,000 Plus BSD: ~$44,600 (Use the Homejourney stamp duty calculator for exact tiers).

Exam Tip: Always calculate the 'Cash Outlay' by adding the downpayment, BSD, and ABSD. For RES exam candidates, this topic falls under Marketing, CPF & Finance in Paper 2. The Prepare app offers practice questions across all 13 RES exam topics to help you master these multi-step scenarios.

Calculating the total cost of a second property purchase requires a three-step process: determining the maximum monthly installment under TDSR, applying the reduced Loan-to-Value (LTV) limits for subsequent loans, and finally adding the applicable Buyer’s Stamp Duty (BSD) and Additional Buyer’s Stamp Duty (ABSD) to the required cash/CPF downpayment.