Mortgage competition is not always good news for bank earnings

Australian mortgage competition can produce two apparently contradictory headlines: borrowers are offered sharper rates while bank investors worry about profitability. Both can be true. Lower pricing may support credit demand, but it can also compress the margin earned on each dollar of lending.

The useful question is not whether competition is “good” or “bad”. It is whether loan growth, funding costs and credit losses are moving fast enough to offset the price paid to win or retain customers.

The signal is in the gap between flow and stock

New loan commitments are a flow. Outstanding housing credit is a stock. The flow can slow before the stock does because existing mortgages remain on bank balance sheets and continue accruing interest.

ABS lending indicators for the June quarter of 2026 show that the seasonally adjusted number of new dwelling loan commitments fell 5.4 per cent from the previous quarter, while their value fell 5.2 per cent. Owner-occupier commitments fell 3.3 per cent by number, and investor commitments fell 8.6 per cent. These series exclude refinancing, so they should not be read as a complete measure of mortgage activity.

The RBA’s May 2026 financial conditions assessment reported that housing credit was still growing at a six-month annualised rate of 7.7 per cent in March, even as new lending and housing price growth were moderating. The RBA also noted that credit growth can lag housing prices. Softer approvals can therefore warn of slower future balance-sheet growth without proving that the current mortgage book is shrinking.

Where the NAB warning fits

Two bank-specific warnings deserve separate attention. In an ABC interview , MST Financial analyst Brian Johnson said NAB mortgage applications had fallen about 15 per cent from the previous quarter and that other major banks were seeing similar weakness. Because the public results do not define that figure, it is better treated as a front-book pipeline warning than as a system-wide lending measure.

A separate ABC Finance Report said NAB expected Australian housing credit growth to slow from 7.5 per cent in 2025 to 2.5 per cent in 2026. That is a forecast, not an observed system outcome. It is also not directly comparable with the RBA’s 7.7 per cent six-month annualised run rate in March: one looks forward over a year, while the other looks backwards over six months.

There is an important counter-signal. NAB’s 2026 half-year results showed housing lending and net interest margin both higher. Benefits from cheaper wholesale funding and deposits partly offset competitive pressure in housing lending. The warning had not yet translated into a simple fall in reported mortgage earnings. The stronger test is whether weaker applications are followed by slower balance growth, heavier discounting and higher credit costs.

What CBA’s FY26 result adds

CBA’s FY26 result provides a useful live test of the same framework. The bank said housing activity had softened from a high base and application volumes appeared to have stabilised in recent weeks. At the same time, it reported growth at or above the system across home lending, business lending, consumer finance, household deposits and business deposits.

That combination is not a contradiction. Applications are a lead indicator; they are not settled loans or outstanding balances. An application must still be approved, drawn, retained and priced profitably before it contributes to earnings. A bank can also grow faster than the system while reducing the value of that growth through aggressive loan discounts or expensive deposit pricing.

Margin tells the price of growth

CBA’s reported net interest margin was 2.05 per cent, three basis points (0.03 percentage points) lower than FY25, while the underlying margin was broadly stable after excluding the effect of liquid assets and institutional reverse repurchase agreements. A replicating portfolio is a modelled set of interest-rate positions used to approximate how balances such as deposits without fixed maturities reprice; CBA’s announcement does not disclose its exact construction. Higher earnings on that portfolio and capital hedges, together with a favourable mix from business lending and deposits, were largely offset by lower lending margins.

This is why a market-share gain is not enough. The result must show that new volume earns an adequate spread after funding, hedging, acquisition and operating costs.

Credit quality is sound, but the direction changed

Loan impairment expense increased 9 per cent to A$788 million from a low base. Home-loan arrears rose to 0.73 per cent and personal-loan arrears to 1.72 per cent. Realised credit losses remained low, and CBA held a A$2.7 billion provision buffer above the losses expected under its central economic scenario.

The result is therefore mixed rather than alarming. Current losses remain contained, but rising arrears and impairment expense make the direction of later-stage arrears, forced sales and realised mortgage losses more important in FY27.

Deposits and investment complete the bridge

Customer deposits accounted for 79 per cent of CBA’s total funding. A large deposit franchise can reduce reliance on wholesale markets, but its earnings benefit still depends on what the bank must pay to retain savings balances when deposit competition intensifies.

Operating costs matter as well. CBA’s investment spend rose 6 per cent to A$2.428 billion and is expected to remain around A$2.4 billion in FY27, with spending directed towards technology infrastructure, modernisation and AI capabilities. Those programs may improve fraud detection, cyber defence, service speed and productivity, but the earnings case needs measurable evidence: lower losses, less manual work, faster handling, better retention or slower expense growth.

Competition changes both sides of the margin

Bank earnings do not depend on the mortgage rate alone. The relevant spread is the difference between what a bank earns on loans and what it pays for deposits, wholesale funding and hedging.

The RBA’s February 2026 credit-market analysis found that the spread between average new variable mortgage rates and the cash rate had narrowed by about 65 basis points since the end of 2019. It attributed the larger part of the narrowing to tighter lending margins, consistent with stronger competition. Cheaper funding cushioned part of that pressure.

That cushion is not unlimited. The RBA’s May 2026 funding-cost review said lending spreads remained well below pre-pandemic levels and major-bank net interest margins had stabilised around historical lows in 2025. Funding conditions can improve while competition prevents banks from keeping the full benefit.

A simple earnings bridge

A useful bank-earnings bridge separates the income calculation, recognised expenses and distributions:

• Net interest income ≈ average interest-earning assets × annualised net interest margin × the fraction of a year covered by the result
• Profit before credit impairment and tax = net interest income + other operating income − operating expenses, using a consistent reporting basis
• Credit-loss assessment: arrears and defaults are risk indicators; the recognised impairment charge or write-back affects the period’s earnings
• Distributions: dividends and buybacks are capital-allocation decisions after considering profit, capital requirements and funding needs, not the same thing as reported profit

NAB’s half-year results report net interest income, average interest-earning assets and NIM together. Those assets include more than home loans. Do not multiply a reported group NIM by the mortgage book alone, or multiply an annualised margin by assets without allowing for a half-year reporting period. Use the bank’s own calculation convention for an exact reconciliation.

For a simplified illustration, A$100 billion of average interest-earning assets at a 2% annualised NIM generates about A$1 billion of net interest income over half a year: A$100 billion × 0.02 × 0.5. Multiplying by an A$70 billion mortgage book would instead give A$700 million, omitting other earning assets. These are fictional inputs, not a forecast or a reconstruction of either bank’s result.

This prevents a common mistake. Faster mortgage growth is not automatically accretive if it was purchased with large discounts or expensive broker acquisition. Conversely, slower approvals do not automatically mean falling profit if deposit costs decline, repricing improves, business lending grows or credit losses stay unusually low.

The same transmission discipline sits behind our broader market-regime framework : a headline matters only after its path into earnings, cash flow and risk has been tested.

Three mortgage regimes

Benign competition

Funding costs fall, mortgage discounts remain disciplined and employment stays resilient. Volumes can moderate without a severe earnings hit because low losses and cheaper funding absorb some of the pressure.

Margin squeeze

Banks compete aggressively for a smaller pool of new borrowers. Approval volumes weaken while customer discounts remain large. Net interest margins fall before arrears rise. This is a profitability problem, not yet a credit crisis.

Credit deterioration

Weak approvals are joined by rising arrears, hardship, unemployment and provisions. Banks then face pressure on both revenue and credit costs. Capital and funding become more important than headline loan growth.

The transition between these regimes matters more than a single monthly approval number.

What to check in every bank result

• Mortgage balance growth versus system growth
• New-loan and back-book pricing, not just advertised rates
• Net interest margin and management’s explanation for its movement
• Deposit mix, deposit beta (the change in average deposit rates divided by the change in the policy rate), wholesale funding and hedging costs
• External and internal refinancing activity
• Arrears, hardship, impaired assets and collective provisions
• Operating expenses and the cost of acquiring loans
• Common equity capital and risk-weighted asset growth

APRA’s quarterly authorised deposit-taking institution statistics provide system and institution-level context for profitability, asset quality, residential mortgages, new approvals and capital. They can help show whether a bank-specific fall in applications is appearing across the system. One bank’s pipeline decline is an early warning to investigate, not by itself a national recession indicator.

For a company-level review, Reading ASX earnings beyond the headline provides a repeatable way to compare reported profit, margins, cash flow, capital returns and guidance.

What would change the view

The benign case would weaken if margins kept falling after funding costs stopped improving, or if arrears and provisions rose across more than one bank. The margin-squeeze case would improve if discounting eased while deposit costs fell. The credit-deterioration case needs confirmation from labour-market stress, repayment arrears and credit costs; slower approvals alone are not enough.

Bottom line

Mortgage competition is helpful to borrowers but ambiguous for bank shareholders. Read the flow of new approvals against the stock of credit, then bridge volume and pricing through funding costs, net interest margin and losses.

The most informative signal is not one falling loan number. It is whether volume, margin and credit quality are deteriorating together.

This article provides general information only and does not take account of your objectives, financial situation or needs. It is not personal financial advice or a recommendation to buy, hold or sell any security.

Sources

• Australian Bureau of Statistics, Lending indicators
• Reserve Bank of Australia, Financial conditions — May 2026
• Reserve Bank of Australia, Recent changes in credit markets — February 2026
• Reserve Bank of Australia, Bank funding costs and lending rates — May 2026
• NAB, 2026 half-year results
• Commonwealth Bank of Australia, FY26 results ASX announcement
• Commonwealth Bank of Australia, FY26 results presentation
• APRA, Quarterly authorised deposit-taking institution statistics
• ABC News, mortgage competition interview
• ABC News, NAB housing-credit forecast