Your borrowing capacity moves with the interest rate, and even a small change in rate can shift your maximum loan. If you are building wealth through property, knowing why helps you plan your next purchase with fewer surprises.
How Does the Interest Rate Affect Borrowing Capacity?
A lower interest rate lets a lender approve a larger loan, because the repayments on each dollar borrowed are smaller. A higher rate does the opposite, so the same income supports a smaller loan.
The twist is that lenders do not assess you at the rate you will actually pay. APRA, the banking regulator, requires lenders to test new borrowers at a rate at least 3 percentage points above the loan product rate. Using our illustrative example rate of 6.75% p.a., a lender would check whether you could afford repayments at 9.75% p.a.
That means every drop in the rate you are offered also drops the rate you are tested at. It is one reason a rate discount matters for capacity and not just for repayments. You can get a feel for your own numbers on our borrowing capacity page, or with any lender calculator.
Example: What a 0.50 Point Rate Discount Does to Your Maximum Loan
A lower rate can lift your maximum loan by a few per cent, and the example below shows how. All figures are illustrative, use a 6.75% p.a. example rate, and ignore living expenses and other debts, which lenders also weigh.
Consider a buyer who plans a 30-year principal and interest loan at 6.75% p.a. At the 9.75% p.a. assessment rate, the most they can service is about $5,155 a month. That supports a loan of roughly $600,000. At the example rate itself, repayments on $600,000 would be about $3,892 a month.
Now suppose a rate discount takes the rate 0.50 percentage points lower, to 6.25% p.a. The assessment rate falls to 9.25% p.a. The same $5,155 a month now supports a loan of around $626,000. That is roughly $26,000 more borrowing power from the same income.
The trade-off is that a discounted rate often depends on your deposit size, your loan to value ratio (LVR) and the lender. A lower rate on paper is also only useful if the loan features suit you. Our home loans team can compare rates across lenders for you.
Variable, Fixed or Split Rate: What Changes for Your Capacity?
For new loans, lenders apply the buffer to the product rate whether it is variable or fixed, so your choice mainly changes your repayments and flexibility rather than escaping the test. A variable rate can move up or down over time. A fixed rate holds your repayments steady for a set period.
Each comes with a cost. Fixing can limit extra repayments and may trigger break costs if you leave early. A variable rate gives you flexibility but exposes you to rate rises. A split loan puts part of the balance on each, which spreads the risk but means managing two loan portions.
If your fixed period is ending, your options widen. Our fixed rate expiry page explains what to check before your lender moves you onto a new rate.
How Can You Improve Borrowing Capacity Before You Apply?
The most direct ways to improve borrowing capacity are to reduce debts, close or lower unused credit card limits, and secure a lower rate. Each one cuts the commitments a lender counts against your income or lowers the rate used in the test.
Credit cards are a common surprise. Lenders generally assess the limit and not the balance, so a card you never use can still reduce what you can borrow. Paying off a personal loan or car loan before applying can have a similar effect.
It also helps to pick the right loan structure for your goal. An interest-only period lowers repayments for a time, but you do not reduce the principal during it, and the repayments rise once principal and interest begins. An offset account can reduce the interest you pay while keeping your cash accessible, though some lenders charge a higher rate or a package fee for it.
If you already own a property, a loan health check can show whether your current rate and structure are holding you back. It can also show whether refinancing would free up capacity for the next purchase.
Why Get Home Loan Pre-Approval Before You Search?
Pre-approval gives you a realistic price range before you bid, so you shop within your means and move faster when the right property appears. It is an indication from a lender based on your finances at that time, not a final commitment.
Because rates and your circumstances can change, a pre-approval may need to be reviewed before settlement. If you plan to buy an investment property, the lender will also look at how the new loan fits with your existing debts, so it pays to talk through the numbers early. Our investment loans page covers how this works for property investors.
A broker can run your numbers against several lenders and show where your capacity is strongest. Call one of our team or book an appointment at a time that works for you, and we will map out what you can borrow and how to lift it.
Frequently Asked Questions
How does the interest rate affect how much I can borrow?
A lower rate means smaller repayments per dollar borrowed, so a lender can approve a larger loan on the same income. A higher rate reduces your maximum loan.
What is the APRA serviceability buffer?
APRA requires lenders to assess new borrowers at a rate at least 3 percentage points above the loan product rate. At an illustrative 6.75% p.a., you would be tested at 9.75% p.a.
Does choosing a fixed rate change my borrowing capacity?
For new loans, the buffer applies to the product rate whether it is fixed or variable. The choice mainly affects repayment certainty, flexibility and possible break costs.
Can unused credit cards reduce my borrowing capacity?
Yes, lenders generally count the card limit, not just the balance. Closing or lowering unused limits before you apply can help.
