Could Australian Mortgage Holders Be Facing Back-to-Back Rate Hikes?

Only a few weeks ago, Australian borrowers were debating when the Reserve Bank might eventually begin cutting interest rates.

Now the question is very different.

Could the RBA increase rates at its 29 September meeting, and then raise them again only five weeks later in November?

Commonwealth Bank Chief Economist Luke Yeaman has warned that possibility cannot be ruled out.

CBA's official base case remains a 25-basis-point increase in November, taking the cash rate from its current 4.35% to 4.60%. But Yeaman told ABC's The Business that the central bank could move earlier in September depending on how inflation risks develop. ABC characterised the outlook as one in which back-to-back increases cannot be ruled out.

That represents another notable shift in Australia's interest-rate conversation.

It is no longer simply:

Will the RBA raise rates again?

Increasingly, the debate is:

How soon could the next increase happen, and could there be more than one?

What the Major Banks Are Now Saying

Australia's Big Four banks now all expect at least one additional RBA increase.

CBA, ANZ and Westpac currently have November as their base case for a 25bp increase to 4.60%.

NAB expects the RBA to move earlier, forecasting a September increase to 4.60%, while also warning that another November hike remains possible if economic activity and inflation remain stronger than expected.

Westpac became the final Big Four bank to move to a hike forecast on 8 September, citing more resilient household incomes and stronger investment associated with the data-centre boom.

So the major-bank consensus has changed considerably.

The disagreement is now primarily about timing and how much tightening could ultimately be required.

What Does "Back-to-Back" Actually Mean?

There is an important detail in the RBA calendar.

The Reserve Bank does not have a Monetary Policy Board meeting in October.

Its next decision is scheduled for 29 September, followed by the next meeting on 3 November.

Therefore, back-to-back increases would mean:

29 September: 4.35% → 4.60%

followed by:

3 November: 4.60% → 4.85%

That would represent another 50 basis points of tightening across two consecutive RBA meetings.

This is not CBA's base-case forecast.

CBA currently expects only the November increase.

But the fact that its chief economist is discussing the possibility of an earlier move highlights how uncertain the inflation outlook has become.

Why Has the Interest-Rate Outlook Changed So Quickly?

The main problem remains inflation.

Australian CPI increased 3.5% over the year to July 2026.

Although that was down from 3.8% in June, the more important trimmed-mean measure remained at 3.6%.

Housing prices within the CPI increased 5.0% annually, while services inflation remained elevated.

The RBA's target is inflation of 2% to 3% over time.

So Australia is not yet comfortably back inside the target.

The Reserve Bank has already raised the cash rate by 75 basis points during 2026, yet Governor Michele Bullock said in August that inflation remained too high and that the Board would increase rates further if necessary.

That is why stronger-than-expected inflation data can quickly change economists' forecasts.

CBA's November Forecast Is Still the Base Case

It is important not to turn CBA's warning into a prediction of two rate hikes.

CBA's formal economics team continues to expect the RBA to increase rates by 25 basis points in November, taking the cash rate to 4.60%.

Its economists shifted to that position after July inflation came in stronger than expected.

CBA also explicitly acknowledged that an earlier September increase was possible.

The new comments from Luke Yeaman effectively widen the range of scenarios borrowers should consider.

Instead of assuming the cash rate stays at 4.35% until November, homeowners now need to recognise that September is also a live possibility.

NAB Already Expects the September Hike

NAB is more aggressive.

Its economics team expects the RBA to increase the cash rate by 25 basis points at the September meeting, taking it to 4.60%.

NAB says July's inflation data showed inflation running hotter than the RBA had anticipated.

More significantly, NAB says the risks are tilted toward another hike in November if economic activity continues to demonstrate resilience.

So the back-to-back scenario CBA says cannot be ruled out is already close to the risk scenario being considered by NAB.

That doesn't mean it will happen.

But it means Australian mortgage holders should probably consider what their finances would look like under both a 4.60% and a 4.85% cash-rate environment.

Why Isn't the RBA Simply Waiting for Inflation to Fall?

Because the RBA is concerned that inflation could become persistent.

In August, the Monetary Policy Board said inflation remained too high and that the Australian economy continued to face capacity pressure.

The Bank also noted that some businesses experiencing higher costs were already increasing prices, while others planned to do so.

The RBA's August Statement on Monetary Policy said inflation was not expected to return to the midpoint of the 2% to 3% target range until around early 2028.

It also assessed the balance of inflation risks as skewed to the upside.

That is a long period for inflation to remain above where the Bank ultimately wants it.

The risk for the RBA is that households and businesses begin treating higher inflation as normal.

Once inflation expectations become embedded, bringing inflation down can become considerably harder.

September Is an Unusual RBA Meeting

The timing of Australia's inflation releases adds another complication.

The next RBA monetary-policy decision is scheduled for 29 September.

But the next official monthly CPI update is not due until 30 September, one day later.

That means the Board's September decision will occur before it sees the next published monthly CPI figure.

The RBA will still have access to extensive labour-market, spending, business, financial-market and liaison information.

But this timetable helps explain why some economists, including Westpac, believe November may be a more natural time to move.

Westpac argues that waiting until November would allow the RBA to assess more data rather than reacting too aggressively to a relatively short history of monthly inflation readings.

NAB sees the risk differently and believes the existing inflation evidence could already justify a September increase.

That difference of opinion is exactly why September has become such an important meeting.

The Oil Shock Adds Another Complication

There is now another inflation risk emerging at precisely the wrong time.

Brent crude has pushed above US$100 a barrel, with Reuters reporting it around US$101 on 10 September as Middle East shipping disruptions intensified.

Higher oil prices do not automatically trigger RBA hikes.

But prolonged increases can flow into Australian petrol, freight, transport and business costs.

That makes the September-versus-November debate even more uncertain.

The RBA has already identified Middle East energy conditions as an upside inflation risk.

If oil prices remain elevated, policymakers may become less confident that inflation will continue easing at the pace previously expected.

What Could One More Rate Hike Mean for Your Mortgage?

The cash rate and individual mortgage rates are not identical.

However, if the RBA increases rates and a lender passes the full increase through to variable mortgage customers, borrowers would face higher repayments.

Consider a simplified example using a $600,000 principal-and-interest mortgage with 25 years remaining.

Assume the borrower's home-loan rate is currently 6.00%.

That means two fully passed-through increases could add approximately $2,225 a year to repayments on this illustrative loan.

For borrowers with larger mortgage balances, the dollar effect would be greater.

These calculations are examples only. Actual mortgage rates, pass-through decisions and repayments vary between lenders and borrowers.

The Real Issue Is the Cumulative Effect

One additional 0.25 percentage-point increase can sound relatively modest.

But homeowners have already absorbed several increases.

The RBA has raised the cash rate by 0.75 percentage points during 2026 alone.

If another 25bp increase occurs, that becomes one full percentage point of tightening during the year.

If two additional increases occurred, the cumulative increase would reach 1.25 percentage points.

For a large mortgage, that is a substantial change.

The financial impact therefore should not be judged by looking at the next individual rate move in isolation.

What matters is how far repayments have moved from where they started.

The Cash Rate Could Reach 4.85% Under a Two-Hike Scenario

The current cash rate is 4.35%.

A September hike would take it to:

4.60%.

Another November increase would then take it to:

4.85%.

Again, 4.85% is not CBA's central forecast.

But it is the logical outcome of two consecutive 25bp increases from today's level.

That makes 4.85% a useful stress-test scenario for borrowers.

Instead of asking only whether you can manage today's repayment, ask whether your household budget could comfortably absorb another 0.25% or 0.50% increase.

A Rate Forecast Is Not an RBA Decision

This distinction matters.

CBA does not set the cash rate.

Neither does NAB, Westpac or ANZ.

The RBA's Monetary Policy Board makes that decision after evaluating incoming economic information.

Forecasts change.

In fact, the rapid change in major-bank forecasts over the past several weeks is evidence of exactly that.

Westpac had previously expected the RBA's next move to be a cut.

It now expects a hike.

CBA previously expected rates to remain unchanged through 2026.

It now expects a November increase and accepts that September is possible.

Forecasts are therefore best treated as scenarios, not promises.

Why Borrowers Should Prepare Rather Than Predict

Trying to perfectly predict the next RBA decision is difficult even for professional economists.

Mortgage holders do not necessarily need to.

A more useful question is:

What happens to my finances if rates rise again?

That calculation is knowable.

A borrower can determine today's mortgage balance, repayment, interest rate, available cash buffer and the impact of a hypothetical 25bp or 50bp increase.

That creates a practical plan regardless of what the RBA ultimately decides.

Check the Rate You're Actually Paying

The first step is simple.

Know your current mortgage rate.

Many homeowners remember the rate they originally received but do not regularly check the rate currently being charged.

That is particularly important because lender pricing can change independently of the RBA.

Banks may adjust rates for different borrower categories, offer new-customer discounts or change pricing based on loan-to-value ratios and competitive conditions.

Your existing mortgage may therefore be relatively competitive, or it may not be.

The only way to know is to compare it.

Could Refinancing Help Before Another Hike?

Potentially.

Another RBA increase does not automatically mean refinancing is appropriate.

But a higher-rate environment makes the comparison more valuable.

Suppose a borrower is currently paying a materially higher rate than competing lenders offer.

Moving to a more competitive rate could potentially offset part of a future RBA increase.

For example, securing a 0.40 percentage-point lower mortgage rate and later absorbing a 0.25 percentage-point RBA increase could still leave the borrower below their original interest rate, depending on lender pricing.

However, refinancing has costs.

Borrowers should consider discharge fees, application costs, government charges, possible fixed-rate break costs, annual package fees and changes to the loan term.

A lower advertised rate does not automatically guarantee a better financial outcome.

Do Not Reset a 20-Year Mortgage to 30 Years Without Checking the Cost

One common refinancing trap deserves particular attention when repayments are rising.

Extending the loan term can make the monthly payment look dramatically lower.

But it can also increase the total interest paid over the life of the mortgage.

A borrower with 20 years remaining who refinances into a fresh 30-year loan may obtain immediate cash-flow relief while remaining in debt for another decade.

That might be appropriate in some circumstances.

But the long-term cost should be understood before making the decision.

Monthly repayment and lifetime interest are two different measures.

Your Offset Account Becomes More Valuable as Rates Rise

Borrowers with functioning offset accounts may also find them increasingly valuable in a higher-rate environment.

Money held in a 100% offset generally reduces the mortgage balance on which interest is calculated.

As the mortgage interest rate rises, each dollar sitting in the offset potentially avoids more interest than it did when rates were lower.

That does not mean borrowers should drain necessary investments or emergency funds simply to increase an offset balance.

But it does mean cash-management strategy becomes more important when mortgage rates rise.

And as ASIC recently warned, borrowers should also ensure that the offset account is actually linked correctly to the mortgage.

Fixed-Rate Borrowers Need to Know Their Expiry Date

People currently on fixed rates may not experience an immediate repayment increase if the RBA moves.

Their key risk is the rate available when the fixed term ends.

Borrowers approaching expiry should therefore know:

the fixed-rate end date, the revert rate, current variable alternatives and the fixed rates available elsewhere.

Waiting until the loan automatically converts can reduce the amount of time available to compare alternatives.

Mortgage Stress Is About More Than Missing Payments

Higher mortgage rates do not need to push households into arrears before they cause financial damage.

A homeowner can continue making every repayment on time while cutting spending elsewhere, delaying savings, using emergency funds or reducing contributions toward other financial goals.

That is why mortgage stress can increase even while actual loan arrears remain relatively contained.

The goal should not simply be to avoid missing payments.

It should be to keep the mortgage sustainable alongside the rest of the household budget.

What Would a 4.85% Cash Rate Mean for Your Household?

The possibility of two increases creates a useful stress test.

Imagine your variable mortgage rate increased another 0.50 percentage points.

Would your budget still comfortably cover repayments?

Would you need to reduce discretionary spending?

Would your emergency buffer remain sufficient?

Would refinancing materially improve the position?

Would using your offset more efficiently help?

Would your current lender negotiate?

You do not need the RBA to actually move twice before answering those questions.

That is the advantage of planning early.

Higher Rates Can Also Reduce Borrowing Capacity

The implications extend beyond existing mortgage holders.

Another rate increase could also affect prospective home buyers.

When mortgage rates rise, lenders assess borrowers using higher repayment assumptions.

That can reduce borrowing capacity.

For someone planning to purchase a home, a higher cash-rate environment may therefore mean qualifying for a smaller loan even if property prices are falling.

This is one reason falling house prices do not automatically create better affordability.

The cost of financing the property matters just as much as the purchase price.

Investors Could Face a Double Impact

Property investors can experience two effects simultaneously.

Their existing variable debt may become more expensive.

At the same time, borrowing capacity for the next investment may decline.

Investor loan assessment can also be influenced by expected rental income, other property debts, living expenses and lender-specific servicing policies.

In a higher-rate environment, structuring finance becomes increasingly important for investors planning multiple purchases.

Self-Employed Borrowers May Need More Preparation

Business owners and self-employed borrowers can face additional complexity.

Higher interest rates can affect personal home-loan repayments while broader economic conditions simultaneously influence business cash flow.

Lenders can also differ substantially in how they assess self-employed income, retained profits, depreciation, business expenses and recent financial results.

For self-employed borrowers considering refinancing or purchasing property, understanding lender policy early can prevent unnecessary surprises.

The Bigger Lesson: The Window for the Next Hike May Be Getting Smaller

The freshest development in this story is not that CBA expects another rate rise.

We already knew that.

The important development is that CBA is no longer treating November as the only realistic window.

September is now possible.

And, according to its chief economist's comments to ABC, the prospect of consecutive September and November moves cannot be completely dismissed.

NAB already expects September.

Westpac, ANZ and CBA currently prefer November.

All four expect another increase.

That means mortgage holders have moved into a period where the timing of the next RBA hike is increasingly uncertain.

Borrowers Don't Need to Wait for 29 September

The next RBA announcement will matter.

But homeowners do not need to wait for it before reviewing their mortgage.

You can calculate the impact of another increase today.

You can compare your current interest rate today.

You can review your offset, loan features and repayment buffer today.

And you can investigate refinancing options before the market knows exactly what the RBA will do.

Preparation is useful whether rates rise in September, November, both meetings, or neither.

Is Your Mortgage Ready for the Next RBA Move?

At Loan & Own Mortgages, we help Australian homeowners, buyers, investors and self-employed borrowers understand how changing interest rates could affect their lending position.

Whether you want to review your current home loan, compare refinancing options, understand how another rate increase could change repayments or prepare your borrowing position for a future purchase, knowing your numbers early can provide greater clarity.

The key question is no longer simply:

Will rates rise again?

It is:

If they do, is your mortgage ready?

Speak with Loan & Own Mortgages to review your current home loan and prepare for the next RBA decision.

Data sources

ABC, The Business, 9 September 2026: Commonwealth Bank Chief Economist Luke Yeaman said CBA's base case remains a November RBA hike but an earlier September increase is possible; ABC reported that back-to-back rate rises cannot be ruled out.

Commonwealth Bank: CBA formally forecasts a 25bp November increase to a 4.60% cash rate, while acknowledging that September is also possible following stronger-than-expected July inflation.

Reserve Bank of Australia: The current cash-rate target is 4.35%, effective from 12 August. The next decision is scheduled for 29 September, followed by the subsequent Monetary Policy Board decision on 3 November.

Australian Bureau of Statistics: Annual CPI inflation was 3.5% in July 2026, while trimmed-mean inflation remained at 3.6%.

NAB: NAB expects a 25bp hike in September to 4.60% and says risks are biased toward an additional November increase if activity remains resilient.

Westpac: Westpac's current base case is a November 25bp increase to 4.60%, driven partly by stronger household income and investment associated with the data-centre boom.

ANZ: ANZ also expects a November increase to 4.60%, citing persistent inflation and resilient household spending.

The mortgage repayment examples are illustrative only and assume a $600,000 principal-and-interest loan with 25 years remaining and a starting mortgage rate of 6.00%. They do not include fees and assume any RBA increases are passed through in full. This article provides general information only and does not constitute personal financial, credit, tax or legal advice.