Before you fall in love with a unit, three rules quietly decide what you can actually buy in Singapore: TDSR, MSR and LTV. They sound like alphabet soup, but the principles are straightforward — and understanding them means you shop with confidence instead of disappointment at the bank.

TDSR — your total debt ceiling

The Total Debt Servicing Ratio is the big one. It caps the share of your gross monthly income that can go towards all your debt obligations combined — not just the home loan, but car loans, personal loans, credit-card commitments and any other mortgages. It applies to most private property purchases and is, for the majority of buyers, the single biggest determinant of the loan ceiling.

The key insight is that everything counts. A car loan or a co-signed mortgage for a family member quietly eats into the income available to service your new home loan. If you're close to the limit, reducing other commitments before you apply can meaningfully lift what you're able to borrow.

MSR — the tighter cap for HDB and ECs

The Mortgage Servicing Ratio is a second, tighter cap that applies specifically to HDB flats and Executive Condominiums bought from a developer. It limits the proportion of your gross monthly income that can go towards the property loan itself. Where MSR applies, it usually binds before TDSR does — so for HDB and EC buyers, this is the number that matters most.

LTV — how much the bank will actually lend

The Loan-to-Value ratio sets the maximum the bank will finance against the property's price or valuation, whichever is lower. The remainder is your downpayment — and a portion of that must be paid in cash rather than CPF. Two factors commonly reduce the LTV you'll be offered: holding other outstanding home loans, and longer loan tenures that stretch past certain age or duration thresholds. The more existing mortgages you carry, the lower the LTV on the next one — which is why your second or third purchase behaves very differently from your first.

How the three rules interact

Think of it as two questions. LTV answers "what's the most the bank will lend against this property?" TDSR and MSR answer "what's the most you can borrow given your income and existing debts?" Your actual loan is the lower of the two. Many buyers fixate on LTV and forget that their income and existing commitments may cap them well below it.

The cash and CPF picture

Beyond the loan, plan for the cash portion of the downpayment, Buyer's Stamp Duty, and — for a second or subsequent property — ABSD, which is often the largest single line item. Mapping out how much comes from CPF versus cash early prevents an unpleasant surprise at the option-exercise stage.

Plan around them, don't get surprised

The practical playbook is simple:

  • Get a fresh in-principle approval before you shortlist, so you shop within a real budget.
  • Pay down or restructure other debt first if you're near the TDSR limit.
  • Model your second-property numbers carefully — lower LTV plus ABSD changes the maths significantly.
  • Confirm current figures with your banker, as rules and rates are reviewed periodically.

How it plays out for different buyers

The three rules interact differently depending on your situation. A first-time buyer with a stable salary and no other loans usually finds LTV, not TDSR, is the binding constraint — the question is simply how much cash and CPF you have for the downpayment. A self-employed buyer often finds income recognition is the sticking point, since banks may haircut variable income; showing clean, consistent records helps. And a second-property buyer faces the triple hit of a lower LTV, the full weight of TDSR including the existing mortgage, and ABSD on top — which is why the second purchase behaves so differently from the first and demands the most planning.

Levers you can actually pull

  • Reduce other commitments — clearing a car loan or personal loan before applying directly lifts the income available under TDSR.
  • Mind the loan tenure — a longer tenure lowers the monthly instalment (helping TDSR) but can reduce your maximum LTV past certain age and duration thresholds. There's a balance to strike.
  • Time the structure — for couples, decisions about whose name holds which property can change both the ABSD and the borrowing picture significantly.
  • Keep cash for the cash portion — remember a minimum slice of the downpayment must be paid in cash, not CPF.

Get advice before you commit

These rules can change, and the right structure depends on your exact situation — your income type, existing properties and family plans. Always confirm the latest figures and seek proper financial advice before signing anything. Want me to connect you with a trusted mortgage broker and model the numbers together before you start viewing? Just ask — it's the first thing I do with every buyer.