UK CPI accelerates to 3.5% on fuel; core edges up | Oct 21, 2026 / ONS / Consumer Price Inflation

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📊 The ONS reported on Oct 21 that UK CPI rose 3.5% y/y in September, up from 3.1% in August and the highest since October 2025.
⛽ Transport, particularly motor fuels, made the largest upward contribution. Motor fuel prices rose 29.8% y/y and petrol averaged 169.5p per litre, the highest since August 2022.
📈 Core CPI rose to 2.8% (Aug 2.6%) and services to 3.7% (Aug 3.4%).
📉 Food inflation stayed at 1.3%, the lowest since September 2021, and slower hotel price growth pulled restaurants and hotels lower.
💡 Transport fell 0.4% m/m, but by less than a year earlier (-2.3%), which also lifted the annual rate. A mixed release. Next: Oct data on Nov 18.

The Ultimate Summary:英国CPI、燃料高主導で3.5%へ加速

UK CPI, September 2026: the data in context

Who publishes this? The Office for National Statistics (ONS) is the UK’s national statistical agency. Its CPI is built on a harmonised methodology developed by Eurostat, which is why it can be compared with euro-area inflation, and it is the measure used for the Bank of England’s inflation target. The ONS also publishes CPIH, which adds owner occupiers’ housing costs and Council Tax and which the ONS calls its most comprehensive measure.

Headline numbers

• CPI: 3.5% y/y (Aug 3.1%), the highest since October 2025
• CPIH: 3.6% (Aug 3.3%)
• Core CPI (ex energy, food, alcohol, tobacco): 2.8% (Aug 2.6%)
• RPI, a legacy measure that is not an accredited statistic: 3.9% (Aug 3.4%)

CPI has risen for three straight months, from 2.6% in June.

International comparison

The ONS notes the UK rate of 3.5% was above France (3.4%) and Germany (3.3%). In the previous release, the August flash estimates for those countries were 2.7% and 2.9%, so inflation also moved higher on the continent. UK CPI is calculated on a basis comparable with EU countries, whereas US CPI from the Bureau of Labor Statistics differs in definition, so direct US comparisons need care.

How to read it

Bullish-on-inflation reading: goods, services and core all accelerated. Calmer reading: core remains below the headline, food inflation is low, and slower hotel price growth was a partial offset.

This note does not forecast market moves; the next data point is the October CPI on 18 November.

解説1:運輸・自動車燃料が最大の押し上げ役

Fuel: what is inside the number

The ONS measures prices of petrol and diesel as part of the transport division of CPI. In September, motor fuel inflation reached 29.8% y/y (August: 23.0%), which the ONS says is the highest since August 2022.

Price levels and monthly moves

• Petrol: +8.2p m/m to 169.5p per litre (a year earlier: -0.2p). It had already risen 9.1p in August, so this is the second sharp monthly rise in a row.
• Diesel: +10.7p m/m to 192.5p, highest since July 2022 (a year earlier: -0.4p).

Other items inside the transport story

Transport contributed 0.94 percentage points to the CPI rate (August: 0.69). Air fares and sea fares added a smaller upward effect; roadside recovery and second-hand cars subtracted. Air fares fell 19.5% m/m, but by less than the 28.8% drop a year earlier, so the annual comparison turned up, mostly on European routes. The ONS notes that flight prices were collected after the Middle East conflict began on 28 February 2026, but it does not attribute the fuel move to it.

Housing side effects

Kerosene prices rose 22.7% y/y (versus -1.4% a year ago) and added to housing and household services inflation.

Policy footnote

The temporary VAT cut under the government’s Great British Summer Savings scheme ended on 1 September. The ONS says it likely raised prices of cultural events and cinema admissions but did not substantially affect headline inflation.

Takeaway

This release shows a clear fuel-driven jump but offers no evidence on persistence. Fuel is volatile, so the October release will be the next check. This note makes no market forecast.

解説2:燃料を除くと?コア・サービス・食品

Beyond fuel: breadth, offsets and noise

The ONS reports both CPI and CPIH. CPIH adds owner occupiers’ housing costs (a rental-equivalence measure of the cost of owning a home) and Council Tax, so its core and services rates sit slightly higher than CPI’s.

What accelerated

• Core CPI 2.8% (Aug 2.6%); core CPIH 3.1% (Aug 2.9%)
• CPI services 3.7% (Aug 3.4%); CPIH services 3.9% (Aug 3.6%)
• CPI goods 3.2%, the highest since September 2023
• Communication 5.8% (Aug 5.3%) and recreation and culture 2.3% (Aug 1.6%)

The ONS says the largest upward contribution to services came from transport services, particularly air fares, where the fall was smaller than a year ago. In recreation, live music (+0.9% versus -8.6% a year earlier) and computer game downloads (+40.0%) contributed.

What offset it

• Restaurants and hotels slowed to 3.8% (Aug 4.1%) as hotel prices rose 2.3% versus 3.8% a year earlier.
• Food inflation was 1.3%, the lowest since September 2021; its contribution to CPIH was 0.11 percentage points.

Housing

Owner occupiers’ housing costs rose 4.0% y/y and contributed 0.70 points to CPIH, the fourth consecutive monthly rise after 16 declines, still well below the 1.31-point peak in January 2025.

Caution

The Food and Drink Federation expects food inflation to arrive later and persist longer; that is an industry view, not a statistical result. Swings in items like air fares mean one month cannot confirm a trend. This note makes no market forecast.

質疑で深める:前年比の「土台」と今後の注目点

Reading base effects, and what comes next

The arithmetic. The annual inflation rate moves roughly with the difference between this month’s m/m change and the m/m change in the same month a year earlier. UK CPI rose 0.4% m/m in September 2026 versus 0.0% in September 2025, consistent with the annual rate rising from 3.1% to 3.5%. In transport, prices fell 0.4% m/m versus a 2.3% fall a year ago, so the smaller drop lifted the annual rate even though transport prices did not rise on the month.

Monthly CPI path

The October 2025 base is +0.4%. That is arithmetic, not a forecast.

Data-quality context

Since February 2026 the ONS has used supermarket scanner data for roughly half of the grocery market. For February, locally collected data would have given CPI of 3.1% versus the published 3.0%, a small difference.

Food

Annual food inflation has been unchanged at 1.3% for three months. The Food and Drink Federation expects it to arrive later and persist longer, citing limited pass-through by manufacturers so far; the ONS cites this as an industry view only.

What to watch

The next CPI release is on 18 November (October data). Compared with the US, where CPI comes from the Bureau of Labor Statistics, UK CPI follows EU-harmonised rules. This note makes no market forecast.