Key Highlights

  • Headline inflation of 4.3 per cent is 0.3 of a percentage point below the 4.60 per cent cash rate target.
  • The trimmed mean was 3.6 per cent and CPI excluding volatile items was 3.7 per cent, all above the 2–3 per cent target range.
  • The Board weighs lagged effects of 100 basis points of tightening, housing and the labour market alongside the inflation data.

September's headline inflation figure now sits just below the cash rate target, a closeness that helps explain why the Reserve Bank's 3 November meeting is drawing so much attention.

Two numbers now frame Australia's monetary policy debate. The first is 4.60 per cent, the Reserve Bank of Australia's (RBA) cash rate target since 30 September 2026. The second is 4.3 per cent, the headline annual inflation rate for September published by the Australian Bureau of Statistics (ABS) on 28 October.

The gap between them is just 0.3 of a percentage point. That proximity matters, because the cash rate is the Bank's main tool for slowing demand and bringing inflation back to its 2–3 per cent target range. This explainer looks at what the two figures mean side by side, and why the comparison sharpens, rather than settles, the debate ahead of the Board's 3 November decision.

Reading the two numbers

The cash rate target is the interest rate the RBA sets for overnight loans between banks, and it flows through to the rates households and businesses pay and receive. The Board lifted it by 25 basis points to 4.60 per cent at its 29 September meeting. That was the fourth increase this year, for a cumulative rise of 100 basis points.

Headline inflation, measured by the Consumer Price Index (CPI), captures the change in prices across a broad basket of goods and services. In the 12 months to September, it rose 4.3 per cent, up from 4.0 per cent in the 12 months to August.

The headline rate, though, is not the only inflation measure the Board watches. The ABS also reported:

  • Trimmed mean (underlying) inflation of 3.6 per cent, up from a revised 3.5 per cent in August.
  • CPI excluding volatile items of 3.7 per cent.
  • A monthly headline rise of 0.8 per cent in original terms and 0.6 per cent seasonally adjusted.

Each is above the top of the target band, and well above the 2.5 per cent midpoint the RBA uses as its reference.

A simple comparison, and its limits

One way commentators often frame the stance of policy is to compare the cash rate with inflation. As a simple calculation, not an RBA measure, subtracting headline inflation of 4.3 per cent from the 4.60 per cent cash rate leaves around 0.3 percentage points. Using the trimmed mean of 3.6 per cent instead leaves around 1.0 percentage point.

That comparison is a rough guide only. It uses inflation over the past year rather than expected future inflation, and the RBA weighs a far wider set of considerations. The Bank also thinks about where rates sit relative to a "neutral" level that neither stimulates nor restrains the economy. At the 29 September media conference, Governor Michele Bullock said of the Bank's estimates of the neutral rate: "we think we're up the top of those sort of ranges".

Still, the narrow gap with headline inflation illustrates why the latest data have drawn attention. With prices rising almost as fast as the cash rate, the question for the Board is whether current settings are doing enough to return inflation to target in a reasonable time.

Why September's print sharpens the question

Several details in the ABS release help explain why the figure has intensified the discussion.

First, the direction of travel. Headline inflation moved from 4.0 to 4.3 per cent in a month, and the trimmed mean edged up from 3.5 to 3.6 per cent.

Second, the drivers. Automotive fuel rose 23.6 per cent over the year, driven by higher world oil prices, and electricity was up 12.8 per cent, mainly because Commonwealth electricity rebates ended. These are prominent, but they are not the whole story: goods inflation was 4.6 per cent and services inflation 4.1 per cent, showing price pressure across both parts of the economy.

Third, the RBA had already flagged the risk. In its 29 September statement, the Board said that "some of the upside risks flagged in August are materialising" and that "global energy prices are now much higher than had been assumed in the August forecasts." In her 28 October opening statement to the Senate Economics Legislation Committee, Governor Bullock repeated that observation and said: "Inflation will therefore likely be higher than was our base case in August."

The other side of the ledger

None of this means the Board's decision is predetermined. The RBA has emphasised factors that cut the other way.

Monetary policy works with a lag, and the Governor told senators the full effects of recent rate rises are yet to be felt. The Board noted in September that its earlier increases "have tightened financial conditions". Housing prices have fallen in most capital cities, and new housing loans have declined. The Governor also said the unemployment rate had risen "a little more than we had expected", even as the labour market appears slightly tighter than previously judged.

Sarah Hunter, Assistant Governor (Economic), told 60 Minutes in an interview broadcast on 25 October: "We know that higher interest rates will bring inflation down". She also said the RBA does not see signs of recession "yet in any of the data that we track", and declined to signal the next decision.

The Board's stated position remains conditional. Its September statement described a readiness to respond, "including increasing the cash rate target further if needed", and said "the Board will be attentive to the data and the evolving assessment of the outlook and risks".

The bottom line

The closeness of 4.3 per cent headline inflation to a 4.60 per cent cash rate is a useful way to see why the inflation debate has sharpened. But the Board looks beyond a single comparison: it pays close attention to underlying measures such as the trimmed mean, to forecasts, to inflation expectations, and to how much of the 100 basis points of tightening this year is still to flow through.

Its decision, and new forecasts in the Statement on Monetary Policy, will be released at 2.30 pm (AEDT) on 3 November, with a media conference at 3.30 pm. The outcome is not yet known. Borrowers and savers may find it worth understanding both numbers, and how the Board's reading of them could shape the months ahead.