Borrowers are facing another increase in mortgage costs after the Reserve Bank of Australia lifted the cash rate to its highest level in 15 years, responding to renewed concerns that inflation is remaining too high.
At its September meeting, the RBA increased the cash rate target by 25 basis points, taking it to 4.6%. The decision marked the fourth interest rate increase of 2026 and extended the tightening cycle confronting households and businesses.
The central bank said inflation remained elevated and that several upside risks identified earlier in the year were beginning to materialise. A major concern has been the widening conflict in the Middle East and its effect on international energy markets.
Global energy prices have risen substantially compared with the assumptions contained in the RBA’s August forecasts. Higher energy costs can feed through the economy in several ways, affecting transport, business expenses and ultimately the prices households pay for goods and services.
The RBA is also balancing those inflation pressures against evidence that economic activity is slowing. While growth has moderated and housing market conditions have softened, the central bank has made clear that returning inflation sustainably to target remains a priority.
The Board said it would continue taking whatever action it considered necessary to achieve that objective, including increasing the cash rate further if economic conditions required it.
Several economic indicators had already increased expectations of a September move before the decision was announced.
The Consumer Price Index rose 3.5% in the 12 months to July 2026, while the unemployment rate subsequently increased to 4.6% in August, its highest level in almost five years. The combination presented the RBA with a difficult policy environment: inflation remained above target at the same time as conditions in the labour market were beginning to soften.
The rate increase has immediate implications for borrowers with variable-rate mortgages.
A 25-basis-point increase can reduce borrowing capacity by approximately $11,200 when calculated using Australia’s average full-time income. That reduction can influence the budgets of prospective buyers because lenders assess how much debt borrowers can service under prevailing and stressed interest-rate conditions.
Existing mortgage holders can also face higher monthly repayments as lenders pass on changes in the official cash rate.
Commonwealth Bank Head of Australian Economics Belinda Allen had expected the RBA to increase rates by 25 basis points to 4.6% at the September meeting after stronger inflation data, higher oil prices and signals from the central bank increased the likelihood of another move.
For a borrower with a $600,000 variable-rate mortgage and 25 years remaining on the loan, a 25-basis-point increase adds roughly $91 per month to repayments, according to the supplied Commonwealth Bank estimate.
That increase may appear relatively modest in isolation, but the cumulative effect of multiple rate rises is more significant. September’s decision was the fourth increase during 2026, meaning many borrowers are already absorbing higher repayments from previous moves.
Higher mortgage costs can influence the housing market in several ways. Existing homeowners may have less disposable income after meeting loan repayments, while prospective buyers may qualify for smaller loans. Investors must also factor higher finance costs into property cash flow and purchasing decisions.
The impact can be particularly noticeable for households that borrowed near their maximum capacity or have large variable-rate balances. Even borrowers who can comfortably meet higher repayments may reassess discretionary spending as a greater share of income is directed towards the mortgage.
For property buyers, reduced borrowing capacity can also affect competition. A buyer who could previously obtain finance at one level may need to lower their purchase budget after lenders recalculate serviceability at higher rates.
The broader challenge for the RBA is that monetary policy operates with a delay. Higher rates are intended to reduce demand across the economy and ease inflationary pressure, but they can also slow household spending, business investment and housing activity.
The central bank acknowledged that economic growth is slowing, but judged that inflation risks still warranted further tightening. Its September statement pointed specifically to higher global energy prices, domestic capacity pressures and stronger-than-expected recent inflation outcomes.
Attention will now turn to the next monetary policy meeting, scheduled for November 3, 2026.
The September increase does not automatically mean another rise will follow. Future decisions will depend on incoming inflation, employment, spending and economic growth data, as well as developments in global energy markets and the Middle East.
For households and property buyers, however, the immediate position is clear. The cash rate now stands at 4.6%, its highest level in 15 years, and borrowing conditions have tightened further.
With four increases recorded during 2026, mortgage serviceability and repayment costs are once again becoming increasingly important considerations for anyone buying, refinancing or holding property with significant debt.
