What is the APRA 3% serviceability buffer?

The buffer is a stress test. APRA requires every regulated lender to assess whether you could still service the loan if interest rates rose 3 percentage points above the actual rate offered. APRA confirmed the 3% setting on 23 July 2025, and again in November 2025. With variable rates around 6% in May 2026, lenders are testing borrowers at roughly 9–9.5%.

Does HECS still affect my borrowing in 2026?

Less than it used to, but only if your balance is small. From April 2025, CBA excluded HECS from serviceability when the debt would be repaid within 12 months and applied a reduced 1% buffer where it would be repaid within 1–5 years. NAB followed in July 2025 by ignoring HECS balances of $20,000 or under. The 2025 government Bill cut all HECS balances by 20%. For borrowers with $40,000–$60,000+ remaining, HECS still meaningfully reduces capacity.

What is APRA's debt-to-income (DTI) cap and who does it affect?

From 1 February 2026, APRA caps each bank's new high-DTI lending — loans where total debt is six times or more of gross income — at 20% of new mortgage flow per quarter, measured separately for owner-occupiers and investors. Roughly 4% of owner-occupier loans currently sit above 6× DTI versus 10% of investor loans, so the cap mostly constrains investor lending. First home buyers usually fall below 6× DTI and are not the primary target.

How much can you really borrow in Australia in 2026?

Q: How do Australian banks calculate borrowing capacity?

Lenders combine four checks. They stress-test your repayments at your actual interest rate plus the 3% APRA serviceability buffer (roughly 9% in May 2026). They subtract a living-expenses figure — usually the higher of your declared expenses and the HEM benchmark for your household. They count existing debts (credit card limits, HECS, personal loans) as liabilities. And they apply APRA's 6× debt-to-income guidance, with a hard quarterly cap on high-DTI lending from 1 February 2026.

Q: How does my credit card limit affect how much I can borrow?

Lenders assess your credit limit, not your balance. A typical bank counts 3.0–3.8% of the limit per month as a committed liability. As a rule of thumb, every $10,000 of credit card limit reduces borrowing capacity by around $50,000. A $30,000 of combined limits across cards you barely use can quietly cost you $150,000 of borrowing power.

A plain-English breakdown of how Australian banks calculate borrowing capacity in 2026 — APRA's 3% buffer, HEM, DTI caps, and the credit card and HECS rules that quietly cut your limit by tens of thousands.

If you've ever opened a bank's online borrowing calculator and felt the number was lower than it should be, you're not imagining it. Lenders in 2026 stress-test borrowers at rates 3 percentage points above what you'll actually pay, apply a conservative living-expenses floor, treat unused credit card limits as if they were maxed out, and apply a hard cap on high-leverage loans. The result is that two households with identical incomes can be told they can borrow amounts that differ by hundreds of thousands of dollars — depending entirely on which lender they walk into and what their declared expenses, debts, and credit limits look like on paper.

This article walks through each of those mechanics, with worked examples for a single on $100,000 and a couple on $200,000. The fastest way to test the maths against your own situation is to use the Calcula borrowing capacity calculator, which models the same APRA buffer, HEM, DTI and credit-card rules described below.

The four levers banks pull

Every Australian bank that's regulated as an Authorised Deposit-taking Institution (ADI) — which means every major bank, all four pillars, and most online lenders — applies four overlapping tests:

The serviceability test — can you repay the loan at your actual rate plus a 3 percentage point buffer?
Living expenses (HEM) — your declared expenses, floored at the Household Expenditure Measure for your household type.
Debt-to-income (DTI) — total debt as a multiple of gross income; APRA prefers below 6×.
Existing liabilities — credit card limits, HECS, BNPL, personal loans, car loans, other property loans.

Each one independently caps the loan size. The smallest cap wins. Most borrowers run into the serviceability test first, but plenty of high earners hit the DTI ceiling and don't realise.

1. The 3% serviceability buffer

When APRA raised the buffer from 2.5% to 3% in October 2021, it was meant for a rising-rate world. We're back in one. The RBA cash rate climbed to 4.35% on 5 May 2026 (RBA cash rate target) and the average new variable owner-occupier rate is approximately 5.66% (RBA Table F6). That means lenders are now stress-testing standard variable applicants at roughly 8.6–9.5% — even though their actual repayment rate is closer to 6%.

APRA confirmed the 3% setting in its 23 July 2025 macroprudential review and again in November 2025, despite industry pressure. The Finance Brokers Association estimated that cutting the buffer 0.5 percentage points to 2.5% would unlock borrowing access for around 270,000 additional Australians (FBAA).

What the buffer actually costs

A single applicant on $100,000 gross income testing a $500,000 loan at 6.0% (actual) versus 9.0% (assessed) sees the assessed monthly repayment jump from about $3,000 to about $4,022 — a $12,000 difference per year that has to come out of after-tax income that's already been HEMmed. The gap between actual and assessed repayments is the single biggest reason why your real budget feels tighter than your bank says it should be — and why you can comfortably make repayments at one bank while another bank declines you outright.

2. The Household Expenditure Measure (HEM)

HEM is the second silent killer of borrowing capacity. Built by the Melbourne Institute at the University of Melbourne, it benchmarks median spending on "absolute basics" (groceries, utilities, transport, children's clothing, phone) and 25th-percentile spending on "discretionary basics" (eating out, alcohol, adult clothing, entertainment). Lenders use HEM as a floor for living expenses — they take the higher of your declared expenses and the HEM benchmark for your household type.

Approximate 2026 HEM monthly figures for major capital cities, mid-income band:

Household type	Approx. monthly HEM	Approx. annual HEM
Single, no children	$1,800–$2,400	$21,600–$28,800
Couple, no children	$2,400–$3,200	$28,800–$38,400
Couple, 1 child	$2,900–$3,400	$34,800–$40,800
Couple, 2 children	$3,100–$4,500	$37,200–$54,000

Industry approximations only. The HEM tables are not publicly published and figures vary by lender.

The Banking Royal Commission (2018) tightened how HEM is applied. Lenders now cross-reference declared expenses against 3–6 months of bank statements, and Open Banking lets some lenders pull your transaction history directly. Two practical implications:

You can't undercut HEM by claiming low expenses. The benchmark is a floor.
You can't beat your own bank statements. If your expenses are clearly higher than HEM, lenders use the higher figure, not HEM.

The window where HEM helps you is narrow: your real spending is already at or below HEM, your bank statements support that, and your declared expenses match.

3. Debt-to-income (DTI) and the new 20% cap

APRA's DTI cap, active from 1 February 2026, is the newest constraint in the 2026 borrowing landscape. Each bank can only have 20% of its new mortgage lending in any quarter at a debt-to-income ratio of 6× or higher. This applies separately to owner-occupier and investor portfolios (APRA, 27 November 2025).

What 6× DTI looks like in practice:

Gross household income	Maximum total debt before the high-DTI zone
$80,000	$480,000
$100,000	$600,000
$150,000	$900,000
$200,000	$1,200,000
$300,000	$1,800,000

Two important things to know. First, the cap restricts how many high-DTI loans a bank can write — it does not ban them. Banks can still lend above 6× within their 20% quota. Second, only about 4% of owner-occupier loans currently sit above 6× versus around 10% of investor loans (APRA Sept 2025 quarter data). The cap is primarily an investor constraint.

For first home buyers in Sydney and Melbourne it can still bite. A couple on $180,000 combined buying at $1.4m is at 7.8× DTI before any other debts. They are not impossible to lend to, but they will face longer queues, more documentation, and higher rates.

4. Liabilities — the credit card trap

This is where most borrowers leave the most capacity on the table. Lenders assess your credit card limit, not your balance. A zero-balance card with a $20,000 limit is treated identically to a maxed $20,000 card. The standard assumption is roughly 3.0–3.8% of the limit per month as a committed liability.

Rule of thumb: every $10,000 of credit card limit reduces borrowing capacity by approximately $50,000 (Canstar's Sally Tindall, via REA Group).

Practical impact:

Combined credit limit	Estimated capacity reduction
$10,000	~$50,000
$20,000	~$100,000
$30,000	~$150,000
$50,000	~$250,000

Three card limits at $20,000 each — easy to accumulate from rewards cards, business cards and a forgotten store card — could be costing you $300,000 of borrowing capacity for free. The fix is straightforward but takes a month: ring each issuer, lower the limit (or cancel the card if you don't use it), and wait for the new limit to flow into Equifax. Most lenders re-pull your credit file before final approval, so the new lower limit lands in the assessment.

BNPL is now a real liability too

Since 10 June 2025, Buy Now Pay Later services are regulated under the National Consumer Credit Protection Act. All providers now hold an Australian Credit Licence, conduct affordability checks, and report defaults to Equifax. For your serviceability assessment that means active BNPL accounts and even unused BNPL limits are treated as liabilities, missed payments hit your credit score, and frequent BNPL usage can be read by lenders as a financial-stress signal.

HECS — better than it was, but still real

Three changes in 2025 made HECS materially less punishing for borrowing capacity:

CBA, 9 April 2025: HECS excluded entirely if it will be repaid within 12 months; reduced 1% buffer (instead of 3%) for 1–5 year payoff windows.
NAB, 31 July 2025: HECS balances of $20,000 or under no longer factor in serviceability.
APRA/ASIC, 30 September 2025: 12-month exception formalised for all ADIs; HELP debt excluded from DTI calculations.
Late 2025: government legislation cut all HECS balances by 20% for around 3 million Australians.

For someone on $100,000 with $12,000 of HECS, the new rules can lift capacity by roughly $55,000 (Attain Loans analysis, August 2025). For someone with $50,000 of HECS still outstanding, the buffer cut isn't available and the impact is much more muted.

Worked examples — what can you really borrow in 2026?

The figures below are indicative — actual amounts vary 20–40% across lenders for the same applicant, driven mostly by HEM band, rental income shading, and HECS treatment. Use them as a sanity-check against the Calcula borrowing capacity calculator, not a quote.

Example 1 — Single on $100,000, no debts, $30,000 HECS

After-tax income (2025-26 brackets): roughly $77,200/year
Less HEM (single, $2,000/month): $24,000/year → $53,200/year available
Less HECS repayment (15% on $33,000 over $67,000): $4,950/year
Net available for repayments: ~$48,250/year, or ~$4,020/month
At a 9.0% assessment rate, $4,020/month over 30 years supports a loan of approximately $500,000

This is consistent with CBA's online calculator, which showed a single on $96,000 with no other debts at $493,000–$550,000 in April 2025 (post the CBA HECS rule change).

Example 2 — Single on $100,000, $20,000 credit card limit, no HECS

Same after-tax income: $77,200
Same HEM: $24,000
Less credit card liability assumption ($20,000 × 3.8% × 12): $9,120/year
Net available: ~$44,080/year, or ~$3,673/month
At 9.0%, $3,673/month over 30 years supports approximately $456,000

The unused credit card limits cost ~$44,000 of capacity. Lower the limits to $5,000 each and you recover roughly $30,000 of that.

Example 3 — Couple on $200,000 combined, no debts, no children

After-tax (split $100k each): roughly $154,400/year combined
Less HEM (couple no kids, $2,800/month): $33,600/year → $120,800/year available
Net available: ~$120,800/year, or ~$10,067/month
At 9.0%, $10,067/month over 30 years supports a loan of approximately $1,250,000
DTI check: $1,250,000 ÷ $200,000 = 6.25× → above the 6× threshold, so the loan would count against the bank's 20% high-DTI quota

In practice, lenders typically come back at $900,000–$1,100,000 for this couple, slightly below the unconstrained maximum. The HEM applied is often slightly higher than the figure used here, and most lenders apply some additional conservatism around the 6× threshold.

Example 4 — Couple on $200,000, one earner on $150k + one on $50k, $40,000 HECS each

This is where lender choice starts to matter most:

HECS treatment: with $40k each remaining, neither qualifies for NAB's $20k exclusion or CBA's 12-month rule
Each pays ~$5k/year in HECS at this income — $10k/year combined
Combined after-tax: ~$152,000, less $33,600 HEM, less $10,000 HECS = ~$108,400/year, or ~$9,033/month
At 9.0%, supports approximately $1,120,000
The same couple at a lender that excludes HECS from DTI but keeps it as a liability could be 5-10% higher

The takeaway is that even modest HECS balances and the lender you choose can swing the answer by $50,000–$100,000.

How rates affect capacity

Each 0.25% RBA move (one standard rate change) shifts borrowing capacity by approximately $12,000–$20,000 for a single average earner and $24,000–$40,000 for a dual-income couple. The 5 May 2026 hike to a 4.35% cash rate has therefore reduced typical capacity by roughly that much for new applicants compared to 30 days earlier.

If the RBA is forecast to hike further, getting your loan assessed sooner — even by a few weeks — can mean the difference between a "yes" at $600k and a "yes" at $580k.

How to maximise borrowing capacity (the boring playbook)

There are five high-leverage things you can do before applying:

Reduce credit card limits to what you actually use. $20,000 of unused limits = roughly $100,000 of borrowing capacity foregone. Drop them to $5,000 each, wait 4–6 weeks for Equifax to refresh, and reapply.
Pay off small debts entirely — personal loans, car loans, BNPL accounts. Closing accounts removes both the monthly liability and the credit limit assumption.
Tidy up bank statements for 3–6 months. Your declared expenses get cross-checked against transactions. Big lifestyle spend in the lookback window inflates the lender's view of your living costs.
Apply through a broker who knows lender HEM bands. Borrowing capacity can swing 20–40% across lenders for the same applicant. A broker who knows which lender uses ANZ-style 90% rental income shading or has the most generous HEM band for your household can find tens of thousands of dollars of capacity that won't show up at your home bank.
Time the application around rate moves where you can. A pre-approval pulled the day before an RBA hike will be assessed at the lower buffer. After the hike, reapply only if rates have moved by 0.25% or more — the noise from buffer movements within a few basis points isn't worth the credit-file enquiry.

What the next 6–12 months might change

Two regulatory shifts are worth watching:

The 12 May 2026 federal budget is widely expected to include changes to negative gearing for new investments and may replace the 50% CGT discount with inflation indexation. If passed, this would reduce after-tax returns on negatively-geared investment property and indirectly tighten investor borrowing capacity.
APRA's annual macroprudential review in late 2026 will revisit the 3% buffer. Industry pressure to reduce to 2.5% is significant. A reduction would lift typical owner-occupier capacity by roughly 5–8%.

Neither is guaranteed. Don't make a buying decision contingent on either change — but if you're at the edge of serviceability, watching the timing matters.

Calculate your own borrowing capacity

Plug your numbers into the Calcula borrowing capacity calculator — it applies the same APRA 3% buffer, a representative HEM benchmark for your household type, the 6× DTI ceiling, and credit card / HECS / BNPL liability rules used by major lenders. It is calibrated to be slightly conservative compared with the most generous lender, which makes it a useful sanity-check before you start an application.

If you're working out whether to use the deposit you have or save more, pair it with the stamp duty calculator and the mortgage calculator to see the full upfront and ongoing cost picture.

A short reminder on advice

This article describes how Australian lenders generally calculate borrowing capacity in 2026. It is not personal financial or credit advice. Lender policies vary, change frequently, and your individual situation — credit history, employment type, deposit source, property type, citizenship status — can change the answer significantly. Speak to a licensed mortgage broker or accredited credit assessor before making decisions that depend on a specific borrowing limit.

For the official source on the regulatory framework, see APRA's macroprudential settings and ATO's HECS/HELP repayment thresholds.

This article provides general information only and is not financial advice. Please consult a licensed financial adviser before making any financial decisions. See our full disclaimer.