When Australian banks assess your home loan application, they do not check whether you can afford the repayments at the advertised interest rate. They test your capacity at a rate roughly 3 percentage points higher — a rule set by the Australian Prudential Regulation Authority (APRA). This serviceability buffer directly limits how much you can borrow: a single buyer earning $100,000 with no other debts might see their maximum loan drop by $90,000 or more compared with an unconstrained assessment. From February 2026, a further restriction took effect: banks must now limit new lending at a debt-to-income (DTI) ratio of 6 or above to 20% of their new residential lending per portfolio. This article explains both measures, how they interact, and what they mean for a typical home buyer in 2026.
The APRA 3% Serviceability Buffer Explained
Since October 2021, APRA has required all authorised deposit-taking institutions (ADIs) to assess new home loan borrowers at the higher of:
- The loan’s actual interest rate plus a 3.0 percentage-point buffer, or
- A minimum floor rate (currently also set at around 3 percentage points above the prevailing rate).
As at May 2026, APRA confirmed the buffer remains at 3%. For example, if a bank offers you a variable rate of 6.00%, your serviceability is tested at approximately 9.00%. If rates fall to 5.50%, the assessment rate drops to about 8.50% — but the buffer itself stays at 3.0 percentage points above whichever product rate applies.
The buffer means that banks calculate your maximum monthly repayment as if interest rates were 3% higher than they actually are. This is a prudential measure designed to ensure you can still service the loan if rates rise — but the practical effect is a lower maximum loan amount than your current income might otherwise support.
How the Buffer Affects Your Maximum Loan Amount
Consider a single applicant with a gross annual income of $100,000, no dependants, and no other debts. At an actual rate of 6.00% assessed over 30 years, a bank calculating affordability with a 30% debt-service-to-income ratio and no buffer might arrive at a borrowing capacity around $550,000. With the 3% buffer applied and assessment at 9.00%, that capacity drops to roughly $440,000 — a reduction of about $110,000, or 20%. The effect is even larger for applicants with existing debts such as credit cards, personal loans, or HECS balances, because the bank subtracts those repayments from the income pool available for the home loan.
Lenders also subtract a notional living expense based on the Household Expenditure Measure (HEM) or your declared spending — whichever is higher. HEM benchmarks vary by household size and income. Single applicants with no dependants and moderate income are quoted a HEM of roughly $1,800–$2,200 per month depending on income tier. This further reduces the income available for loan repayments.
The New DTI Restriction (February 2026)
From February 2026, APRA directed that no more than 20% of each ADI’s new residential lending in a rolling period can be to borrowers with a debt-to-income ratio of 6 or above. DTI is calculated as total debt divided by gross annual income. For a borrower earning $100,000, a DTI of 6 means total debts of $600,000. If your existing debts plus the proposed home loan push your DTI to 6 or above, your application falls into the restricted 20% pool.
This does not mean borrowers above DTI 6 are automatically declined. But it means each lender has a limited quota for such loans, which can result in stricter scrutiny, higher required deposits, or simply being told “not at this time” once the quota is filled. For first-home buyers in expensive markets such as Sydney or Melbourne — where a median-priced home may require a loan of $700,000 or more — the 20% quota is a meaningful constraint.
What Buyers Can Do to Maximise Borrowing Capacity
Several factors improve your assessed borrowing power under the current rules:
- Reduce existing debt: Paying off a credit card or personal loan both lowers your DTI and frees up income in the bank’s serviceability calculation. Even a $5,000 credit card limit can subtract more from your borrowing capacity than the balance owed, because lenders often assess the limit rather than the balance.
- Close unused credit accounts: Open credit cards and store cards count as contingent liabilities regardless of whether you use them.
- Increase your deposit: A larger deposit means a smaller loan, which lowers your DTI and your monthly repayment in the assessment.
- Joint application: A second income can significantly lift the combined borrowing limit, though both applicants’ debts and living expenses are counted.
- Choose a lender carefully: Different ADIs apply the buffer and HEM benchmarks with minor variations. A mortgage broker can compare across multiple lenders.
Other Factors That Lenders Consider
Beyond the APRA buffer and DTI cap, lenders assess your credit history, employment stability (typically requiring 3–6 months in a permanent role or 2 years of consistent self-employment records), the loan-to-value ratio (LVR), and the property’s valuation. Lenders Mortgage Insurance (LMI) is typically required if your deposit is below 20%, adding to the upfront cost but not changing the serviceability assessment.
Frequently Asked Questions
Has APRA indicated when the 3% buffer might change?
APRA reviews its macroprudential settings periodically and confirmed in May 2026 that the buffer remains at 3%. No public timetable for a change has been announced. Any future adjustment would likely respond to sustained changes in interest rates or financial stability risks.
Is the DTI cap a hard limit?
No. It is a portfolio-level restriction on lenders, not an individual ban. Your application can still be approved above DTI 6, but the lender must manage its total such lending within the 20% cap.
Does the buffer apply to fixed-rate loans?
Yes. All new owner-occupier and investment home loans are assessed with the buffer. For fixed-rate loans, the buffer applies above the fixed rate, or above a reversion rate if the fixed period is shorter than the assessment period.
How does HECS/HELP debt affect borrowing capacity?
A HECS debt reduces your take-home pay through compulsory repayments, and lenders subtract this from your income in serviceability calculations. A HELP debt of $30,000 at a $75,000 salary costs about $821 in annual repayments — a relatively small hit to borrowing capacity. But a large HELP debt at a high income can be material.
Can I get pre-approval above DTI 6?
Some lenders will issue pre-approval above DTI 6 if quota is available, but pre-approvals are not binding offers. Be prepared for the loan to be declined or the amount reduced if the lender’s DTI quota has been exhausted by the time you formally apply.
Data Sources
All APRA requirements cited are drawn from APRA’s published prudential standards and public statements, including the confirmation of the 3% buffer in May 2026 and the February 2026 DTI directive.
- APRA — Residential mortgage lending: https://www.apra.gov.au/residential-mortgage-lending
- APRA — Macroprudential policy framework: https://www.apra.gov.au/macroprudential-policy
- APRA — DTI restriction announcement (February 2026): https://www.apra.gov.au/news-and-publications
- Moneysmart (ASIC) — Borrowing power calculator: https://moneysmart.gov.au/home-loans/how-much-can-i-borrow
- APRA — Monthly Authorised Deposit-taking Institution Statistics: https://www.apra.gov.au/monthly-authorised-deposit-taking-institution-statistics
Data current as at July 2026. APRA policy settings can change; verify with APRA and your lender before making borrowing decisions.
Disclaimer
This article provides general information only and does not constitute financial, credit, or legal advice. Your borrowing capacity depends on your personal financial circumstances, the lender’s specific credit policies, and APRA’s macroprudential settings at the time of application. Consult a licensed mortgage broker or financial adviser before applying for a home loan.