A sharp rise in the price of fuel, along with a jump in the cost of air fares and tickets for entertainment events, all helped push up the overall rate of UK inflation last month.
While many household groceries also saw their prices accelerate, some items did see an easing of inflation, as did the cost of visiting restaurants and hotels.
The biggest factors contributing to the increase in the overall rate from 3.1% to 3.5% were petrol and diesel, according to Consumer Prices Index data from the Office for National Statistics (ONS).
The cost of filling up with petrol last month was 26.5% higher year on year, compared with an annual rise of 20.2% in August.
Diesel saw an even steeper jump of 35.8%, compared with 27.8% in August.
The acceleration in fuel price inflation is linked to both the ongoing conflict between Russia and Ukraine and renewed hostilities in the Middle East, which have disrupted the global supply of oil and other products.
Air fares were up 3.9% year on year in September, following a drop of 8.0% in August.
This was due to European routes, where fares fell by less in September 2026 than they did in September 2025, the ONS said.
Changes in the annual rate of inflation for air travel can be volatile, due to factors such as the timing of school holidays, seasonal deals on prices, plus the impact of global events.
Elsewhere, the average cost last month of tickets to cinemas, theatres and concerts was up 9.6% year on year, compared with a rise of 6.0% in August.
The price of visiting museums, libraries and zoos was up 4.4%, compared with 2.6% the previous month.
Among food and drink items, mineral water, fish, rice, crisps, eggs and whole milk all saw a higher rate of inflation in September than in August.
Olive oil swung from negative inflation in August, with prices on average 2.8% lower than a year ago, to positive inflation in September of 0.7%.
There was a similar swing in the cost of mobile phone equipment, which was 0.2% lower in August than a year earlier, but 3.7% higher in September.
The increase in the overall rate of inflation would have been steeper had prices not eased in some areas – particularly for hotels and similar accommodation, where the rate more than halved from 2.7% in August to 1.2% in September.
Pasta and couscous, tea, soft drinks, fresh fruit and breakfast cereals all saw a lower rate of annual inflation last month than in August.
Margarine, low-fat milk and men’s clothing swung from positive inflation in August to negative inflation in September, while pizza and quiche, potatoes and second-hand cars saw a larger year on year fall in cost than in the previous month.
Below are some examples of how the Consumer Prices Index (CPI) inflation rate has eased or accelerated.
Two figures are listed for each item: the average rise in price in the 12 months to September, followed by the average rise in price (in brackets) in the 12 months to August.
– Examples where annual inflation has accelerated, ranked by the size of the change:
Passenger air travel: September up 3.9% year on year (August down 8.0%)Diesel: up 35.8% (up 27.8%)Petrol: up 26.5% (up 20.2%)Mobile telephone equipment: up 3.7% (down 0.2%)Cinemas, theatres, concerts: up 9.6% (up 6.0%)Olive oil: up 0.7% (down 2.8%)Mineral or spring waters: up 10.8% (up 8.9%)Museums, libraries, zoological gardens: up 4.4% (up 2.6%)Fish: up 8.3% (up 6.6%)Rice: up 2.7% (up 1.3%)Crisps: up 4.5% (up 3.1%)Gas: up 9.8% (up 8.6%)Whole milk: up 2.2% (up 1.4%)Eggs: up 2.0% (up 1.5%)
– Examples where annual inflation has eased:
Pasta products & couscous: September up 3.3% year on year (August up 7.2% year on year)Margarine & other vegetable fats: down 0.8% (up 1.5%)Tea: up 0.5% (up 2.5%)Soft drinks: up 3.3% (up 5.0%)Pizza & quiche: down 5.6% (down 3.9%)Hotels & similar accommodation: up 1.2% (up 2.7%)Low-fat milk: down 0.2% (up 0.8%)Fresh or chilled fruit: up 1.3% (up 2.3%)Garments for men: down 0.5% (up 0.3%)Second-hand cars: down 3.2% (down 2.5%)Potatoes: down 1.3% (down 0.6%)