How the RBA cash rate flows through to your mortgage repayment

The cash rate decision made by the Reserve Bank of Australia (RBA) board is the single most influential factor in determining how much you pay each month on your home loan. Yet the path from a 2:30pm announcement to a change in your bank balance is not instantaneous. It passes through funding markets, lender pricing committees, and loan contract terms before reaching your repayment amount. Understanding this transmission mechanism — and the typical time delays involved — can help you anticipate cash flow changes and make informed decisions about fixing, switching, or staying put.

The RBA board decision: from announcement to market pricing

The RBA board meets eight times a year. At 2:30pm on the scheduled Tuesday, the board releases its decision on the cash rate target. As of mid-2026, that target stands at 4.35 per cent, where it has remained since late 2025. Within seconds of the announcement, money-market traders adjust the implied overnight rate, and the yield curve shifts. For borrowers, this is the starting gun — but not the finish line.

While the cash rate directly influences the cost of overnight funds between banks, its effect on longer-term interest rates (such as three-year swap rates) is indirect and can be smaller or larger depending on market expectations about future moves. The first stage of transmission has already occurred moments after the press release.

The first stage: changes in bank funding costs

Lenders rely on a mix of funding sources to write mortgages. Approximately 30-35 per cent comes from customer deposits, 20-25 per cent from wholesale debt markets (covered bonds, term deposits, and syndicated loans), and the remainder from capital markets and securitisation. The RBA cash rate directly affects the cost of deposits and short-term wholesale funding.

· A rate cut lowers the interest paid on savings accounts, reducing the bank’s cost of deposit funding. · A rate hike increases the cost of overnight index swaps, which banks use to hedge floating-rate debt. · Fixed-rate funding responds more to swap rates (e.g., 3-year swap at 4.50%) than to the cash rate directly.

In 2026 the spread between the cash rate and the average three-year swap rate is about 15 basis points, meaning fixed-rate borrowers are influenced more by bond market sentiment than by the RBA’s exact number.

How lenders decide their new rates

Once a bank’s treasury team calculates the net change in funding costs, the pricing committee — composed of credit risk, retail, and finance executives — decides whether to pass on the full amount, a partial amount, or nothing at all. The decision is not automatic; it balances three factors:

· Competitive pressure: If a major lender moves quickly, others often follow within days to retain market share. · Regulatory constraints: APRA’s 3 per cent serviceability buffer and the 6x gross income cap on debt-to-income ratios (effective February 2026) limit how much new lending the bank can write. A rate cut that stimulates demand may be muted by these caps. · Profit margins: In 2026 the average net interest margin on owner-occupier variable loans is around 2.1 per cent. Lenders are reluctant to cut into that unless forced by competition.

Typical lag times vary. A standard variable rate change is announced within 1-2 weeks of the RBA decision and applied from the first day of the following month. Fixed-rate products often adjust within 24-48 hours because they reference liquid swap markets.

From rate change to your monthly repayment

The exact date your repayment changes depends on your loan’s interest-setting clause. Most variable-rate home loans state that the new rate applies from the next interest‑calculation period, usually at the start of the month following the announcement.

Example: The RBA cuts rates by 0.25 per cent on 4 August 2026. Westpac announces a full pass-through on 13 August, effective from 1 September. Your August repayment is unchanged; the lower amount first appears in the September direct debit.

To see the dollar difference, consider a $600,000 principal-and-interest loan at the current lowest variable rate of 5.69 per cent (for owner-occupiers with 20% equity). Monthly repayment: $3,485. After a 0.25 per cent cut to 5.44 per cent: $3,390. That’s a saving of $95 per month, or $1,140 a year.

If you are paying the benchmark variable rate of 6.24 per cent (standard variable without discounts), the same 0.25 per cent cut reduces your repayment from $3,690 to $3,587, saving $103 per month.

Timing differences: variable vs fixed rate loans

For borrowers with a fixed-rate loan, the RBA decision has no direct impact until the fixed term expires. Your interest rate is locked for one to five years, so the cash rate moves do not change your monthly payment. However, new borrowers applying for a fixed rate will see those rates adjust almost immediately as lenders re-price after the RBA announcement.

In 2026, three-year fixed rates range from 5.3 per cent to 5.6 per cent depending on the lender and loan-to-value ratio. If the cash rate falls further, fixed rates will drop in sync with swap rates, often before variable rates change.

One important consideration for borrowers approaching the end of a fixed term: if the RBA has cut rates during your fixed period, your new variable rate will be lower than it otherwise would have been. Conversely, if rates have risen, you will face repayment shock when your loan rolls off.

The role of APRA and regulatory settings

APRA’s macroprudential tools affect how quickly transmission flows through to new lending, but they do not change the timing of repayment changes for existing borrowers. The 3 per cent serviceability buffer ensures banks stress-test borrowers at a rate at least 3 per cent above the current loan rate. For example, at a 5.69 per cent variable rate, the assessment rate is 8.69 per cent. This buffer does not alter your actual repayment, but it can make lenders more cautious about passing on cuts if they worry about future affordability.

The debt-to-income cap of 6 times gross income, introduced in February 2026, limits how much new debt a borrower can take on relative to income. This cap affects eligibility, not repayment timing.

The First Home Guarantee (FHBG) scheme, updated from July 2026, now allows eligible borrowers to buy with a 5 per cent deposit and no income cap, provided the property price is within city caps: Sydney $1.5 million, Brisbane $1 million, Melbourne $950,000, Perth $850,000. While this does not change the transmission mechanism, it influences competition among lenders for first-home buyers, which can affect how quickly they adjust rates for that segment.

What this means for borrowers in 2026

With the RBA cash rate steady at 4.35 per cent, variable mortgage rates remain elevated by historical standards, but they are well below the peak of 7.5 per cent seen in January 2023. The lowest variable rates available to owner-occupiers with good equity and clean credit are around 5.69 per cent. That gap of 1.34 per cent above the cash rate is smaller than the long-term average of about 2.0 per cent, indicating strong competition.

If you are on a variable rate above 5.69 per cent, there is likely room to refinance — provided you meet the APRA serviceability test and your loan-to-value ratio is under 80 per cent. Refinancing from a 6.24 per cent standard variable to 5.69 per cent on a $600,000 loan saves $115 per month.

Fixed-rate borrowers should compare the break cost of exiting early with the potential saving from a lower variable rate. Break costs for fixed loans in 2026 have eased as swap rates have fallen, but they can still run into thousands of dollars.

For those considering fixing now, the trade-off is between the certainty of a known rate (e.g., 5.3 per cent for three years) and the possibility of further RBA cuts later in 2026 or early 2027. Market pricing implies a 45 per cent chance of a 0.25 per cent cut by November 2026.

Frequently asked questions

1. How long after an RBA rate cut does my monthly repayment decrease?

Typically 1-2 months. The lender announces its new rate within 1-2 weeks, then the change takes effect from the first day of the next month. Your first reduced repayment appears about 6-8 weeks after the RBA decision.

2. Will I see the new rate on my online bank statement immediately after the RBA announcement?

No. The lender must update its system. Most banks send a notification letter or email 5-7 business days after the board meeting confirming the effective date and new repayment amount.

3. If I’m on a fixed rate, does the RBA decision affect me at all?

Not during the fixed term. Your interest rate and repayment are locked. However, when your fixed term ends (e.g., in 12 months), the variable rate you roll onto will reflect all intervening RBA decisions.

4. How much would my repayment change on a $500,000 loan with a 0.25 per cent move?

At 5.69 per cent variable, a $500,000 loan has a repayment of $2,904 per month. Dropping to 5.44 per cent reduces it to $2,828, a saving of $76 per month. Conversely, a 0.25 per cent rise to 5.94 per cent increases the repayment to $2,980, an extra $76 per month.

5. Why don’t all lenders pass on the full RBA change immediately?

Lenders have different funding mixes, profit targets, and competitive strategies. A lender with a high proportion of term-deposit funding may pass on less if those deposit rates have not fallen. Others may hold back to protect margins, then pass on more later if they lose market share.

Sources

· Reserve Bank of Australia – Cash Rate Target and Minutes of Board Meetings (www.rba.gov.au) · Australian Prudential Regulation Authority – Macroprudential Policy Measures (www.apra.gov.au) · Housing Australia – First Home Guarantee Fact Sheet (www.housingaustralia.gov.au) · State Revenue Offices – First Home Buyer Duty Concessions (e.g., Revenue NSW, SRO Victoria, QRO, RevenueWA)

Calculate your own repayment

Use our loan repayment calculator to see how a rate change affects you. Enter your loan balance, current rate, and any new rate to compare monthly repayments instantly.

Want to see how much you could save? Click the button below to open an interactive calculator right here.

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· Loan features comparison 2026 – offset accounts, redraws, and rate locks that affect your payment timing. · Fixed vs variable rate loans 2026 – which structure gives you the best protection against future RBA moves. · Refinancing break-even calculator 2026 – work out how long it takes to recover the costs of switching lenders.