UK Inflation Hits 3.5% in September, Fuel Costs Bite

UK consumer price inflation rose to 3.5% in the 12 months to September 2026, up from 3.1% in August, according to the Office for National Statistics. The increase, driven largely by a surge in motor fuel costs, came in hotter than the 3.4% rate economists polled by Reuters had expected, and now has traders betting the Bank of England will raise interest rates at its next meeting.

What the official data show

The ONS's Consumer Prices Index (CPI) bulletin, released on October 21, 2026, confirmed that the Consumer Prices Index (CPI) rose by 3.5% in the 12 months to September 2026, up from 3.1% the previous month, and on a monthly basis, CPI rose by 0.4% in September 2026. The broader CPIH measure, which includes owner-occupiers' housing costs, rose by 3.6% in the 12 months to September 2026, up from 3.3% the previous month, with a 0.4% monthly rise in September 2026. Underlying price pressure also firmed: core CPI, which excludes energy, food, alcohol and tobacco, rose by 2.8% in the 12 months to September 2026, up from 2.6% in August, while the CPI services annual rate rose from 3.4% to 3.7%.

CNBC, which first flagged the release, reported that U.K. inflation rose by a hotter-than-expected 3.5% in the 12 months to September, driven by the surging cost of motor fuels, and that economists polled by Reuters had been forecasting an annual inflation rate of 3.4%. Trade outlet Drapers, citing the same ONS release, quoted ONS chief economist Grant Fitzner saying "Inflation climbed notably in September to its highest annual rate in almost a year. Increased fuel prices were again the main driver, with the cost of diesel the highest since July 2022." Drapers also noted the context that September's was the highest CPI rate since the 3.6% recorded in October 2025, meaning the current reading, while elevated, has not yet reached last autumn's peak.

Why fuel was the biggest driver

Financial news service Investing.com, drawing on the same ONS dataset, reported that overall motor fuel prices rose 29.8% in the 12 months to September, compared with 23.0% in the 12 months to August, while prices in the wider transport category rose 6.6% in the 12 months to September, up from 4.6%. That single category accounts for most of the month-on-month acceleration in the headline rate. It is a volatile, globally driven input: fuel costs can swing with oil markets and refining margins in ways largely outside the Bank of England's control, which is why policymakers tend to look past the headline number toward the core and services measures when deciding on interest rates.

What it means for the Bank of England's next move

The Bank of England's Monetary Policy Committee last met on September 17, 2026, when it voted 6-3 to keep Bank Rate unchanged at 3.75%, in line with market expectations, with three members preferring a 25-basis-point increase to 4%. Its next scheduled decision falls on November 5, 2026. Following the hotter CPI print, CNBC reported that markets are pricing in a 98% chance that the Bank of England raises its key interest rate by 25 basis points to 4% next month, according to LSEG data, with the majority of traders also pricing in a further hike of the same size at the central bank's final meeting of the year in December. A separate market-pricing tracker, Blue Gamma, put the implied probability of a November hike at a slightly lower 90% based on overnight index swap pricing taken a day before the CPI release, a reminder that these are dated, model-based market odds rather than a central bank commitment, and they can move once new data lands.

Capital Economics senior economist Ashley Webb offered a similar call in comments to HomeOwners Alliance, saying his firm's forecast is for the Bank of England to raise interest rates by 25 basis points twice more, from 3.75 per cent at the next policy meeting in November and to 4.25 per cent in February, rather than a longer run of hikes some other forecasters had floated. None of this is a guarantee: the MPC's actual vote on November 5 could still diverge from what swaps markets and bank economists are currently pricing, particularly if October data shifts the picture again.

What readers should take from this

For anyone with a variable-rate mortgage, a savings account, or plans to borrow, the practical read is that borrowing costs are more likely to rise than fall over the next two Bank of England meetings, based on current market pricing and bank forecasts cited above, not a certainty, but the direction the evidence points. Savers with variable-rate or easy-access accounts could see modestly higher returns if the Bank Rate does rise to 4% in November, since UK banks often move deposit rates in step with Bank Rate changes, though not always by the full amount or immediately. What remains unknown from this release alone is how the Bank's nine-member committee will actually vote on November 5, how October fuel prices move before then, and whether services inflation, which the ONS shows already running at an annual 3.7%, continues to firm independently of fuel costs, which Fitzner's own comments about diesel suggest is the trend officials are most focused on.