Mortgage capacity, and what the bank is actually testing: known limitation 1

The two tests are usually quoted separately and by different people, so a buyer hears the loan to value number from an agent and assumes it is their capacity. The income test is frequently the binding one and nobody mentions it until the application.

Mortgage capacity, and what the bank is actually testing: known limitation 2

Acquisition costs cannot be borrowed. The deposit is the gap left by the loan to value cap plus the transfer fee, agency, trustee and registration on top, and a buyer who has saved only the headline deposit is short.

Mortgage capacity, and what the bank is actually testing: known limitation 3

The debt burden ratio counts commitments rather than balances. A credit card with a limit and no balance can still consume capacity at some lenders, and a car loan with a year left counts at its full monthly payment.

Playbooks / Property

Mortgage capacity, and what the bank is actually testing

Mortgage capacity is set by two tests applied at once, a loan to value cap that limits the loan against the property and a debt burden ratio that limits it against your income, and the smaller of the two answers is the only one that matters.

The rule

Almost everyone works out what they can borrow the wrong way round. They find a property, then ask whether the bank will fund it. The bank has already decided, months earlier, using two tests that have nothing to do with the property you happen to have fallen for.

Both run at once. One asks how much the bank will lend against the asset. The other asks how much it will lend against you. Your capacity is whichever answer is smaller, and the two are quoted by different people who rarely mention the other exists.

Test one: the property

A loan to value cap, expressed as a percentage of the purchase price. Regulators set the ceiling, banks sit at or below it, and the number moves with whether you are a resident, whether it is your first property, whether it is a villa or an apartment, whether it is off-plan, and the price bracket.

This is the test everyone knows, because it produces the deposit figure that gets quoted in every advertisement.

And it is the one that gets understated, because the deposit is not the only cash required. The transfer fee, agency commission, trustee fee and mortgage registration are paid on top and cannot be borrowed. A buyer who has saved exactly the headline deposit is short by the whole of transaction cost drag, which in Dubai runs to several percent of the price before anyone has moved in.

Test two: you

A debt burden ratio: a cap on total monthly debt payments as a share of monthly income. Every committed payment counts, not just the mortgage. Car finance, personal loans, credit cards, and at some lenders school fees.

The mortgage has to fit in what is left after everything else.

This is the test that surprises people, for a reason worth naming: it is assessed on commitments, not balances. A credit card sitting at zero can still consume capacity at lenders who count a share of the limit. A car loan with eleven months left counts at its full monthly payment, not at what remains owing. Clearing a small loan before applying can therefore buy more capacity than saving the same amount toward the deposit, which is not intuitive and is occasionally worth a great deal.

And the income side is narrower than most people assume. Bonus and commission are discounted or excluded depending on how long they have been consistent. Rental income from the property being purchased is usually not counted, or counted at a heavy haircut, which is why a purchase that services itself on paper can still fail this test outright.

The stress test underneath both

Banks do not qualify you at the rate they quote you. They qualify at a higher one, so that a borrower who passes today still passes after rates move.

This matters more than it sounds. The affordable purchase price at the advertised rate is not the number the underwriter is using, and the gap between them widens as rates rise. Re-run your payment two percentage points higher and confirm it still clears. If it does not, you are looking at properties the bank has already declined.

It is the same discipline the cash on cash return framework applies from the other direction: a deal that only works at today's rate is a deal with no room in it.

What this changes about how you search

Work out both numbers first, take the lower, subtract the acquisition costs from your cash, and search below that. It takes an afternoon and it removes an entire category of disappointment. Everything after that point is due diligence on the specific unit.

It also reframes what a mortgage is for. The two tests together describe how much risk a bank is willing to take on the pair of you, the asset and the borrower. That is useful information about the purchase, not just an obstacle to it. When the income test is binding, the bank is saying the property is fine and you are stretched. When the loan to value test binds, it is saying you are fine and the asset carries more risk than it will fully fund.

Both are worth hearing before deciding whether to argue with them.

The arithmetic

Test one, the property Maximum loan = Price x LTV cap Deposit needed = Price - Maximum loan + all acquisition costs, which cannot be borrowed Test two, the borrower Maximum total monthly debt = Monthly income x DBR cap Room for this mortgage = Maximum total monthly debt - every other committed payment (car, cards, personal loans, school fees where counted) From a payment back to a loan Loan = Payment x (1 - (1 + r)^-n) / r where r is the monthly rate and n the number of months Your capacity is the LOWER of the two, always. The stress test underneath both Banks qualify the payment at a rate above the one they quote. Re-run the payment two percentage points higher and confirm it still clears, because that is the test being applied.

Where it breaks

The two tests are usually quoted separately and by different people, so a buyer hears the loan to value number from an agent and assumes it is their capacity. The income test is frequently the binding one and nobody mentions it until the application.
Acquisition costs cannot be borrowed. The deposit is the gap left by the loan to value cap plus the transfer fee, agency, trustee and registration on top, and a buyer who has saved only the headline deposit is short.
The debt burden ratio counts commitments rather than balances. A credit card with a limit and no balance can still consume capacity at some lenders, and a car loan with a year left counts at its full monthly payment.
Rental income from the property being bought is usually not counted, or is counted at a heavy discount. A purchase that services itself on paper can still fail the income test entirely.
The rate you qualify at is not the rate you are quoted. Banks stress the payment upward, so the affordable purchase price at the advertised rate is not the one the underwriter is working with.

When to use it

Before viewing anything, so the search is over properties you can actually finance rather than a shortlist that collapses at the application. Then again on any change to income or committed debt, because both tests move.

Run it on your own numbers

The Net Rental Yield does this arithmetic for you, in your currency, in about thirty seconds.

Open the calculator

Sources

Last reviewed 28 August 2026. Commercial relationship disclosure: the author works in Dubai real estate brokerage. See the disclosure standards. Disclosure standards.