UK inflation unexpectedly accelerated in July, reaching its highest rate in more than 18 months, official figures show.

The Consumer Prices Index (CPI) rose to 3.8%, up from 3.6% in June, according to the Office for National Statistics (ONS). Economists had forecast a smaller rise of 3.7%.

The Retail Prices Index (RPI), used to calculate next year’s rail fare increases, also jumped from 4.4% in June to 4.8% in July. That could mean passengers face fare hikes of nearly 6% in 2026, if the government repeats last year’s formula.

The Bank of England has warned that inflation could reach 4% by September, fuelled by rising food and energy prices. Food inflation climbed to 4.9% in July, up sharply from 4.5% the month before, while transport and hospitality costs also added upward pressure.

Some economists even pointed to Oasis’s reunion tour as a factor behind pricier hotel stays in cities including Manchester and London, echoing the so-called “Taylor Swift effect” on prices last year.

Kris Hamer, director of insight at the British Retail Consortium, said: “Households are once again seeing the cost of their weekly shop climb, with food inflation now up by 1.9 percentage points in just four months.

“This surge has been a key driver behind headline inflation, alongside a rise in transport costs, piling fresh pressure on families already being forced to cut back.

“Retailers have been doing everything they can to prevent price rises but the swathe of costs they now face has left them no room to manoeuvre.

The recent administration of Claire’s Accessories is yet more evidence of the pressure the industry is currently facing. The Chancellor must avoid burdening the industry with even more taxes this autumn.”

The figures come as Chancellor Rachel Reeves faces increasing pressure to curb price rises, with the Bank warning food inflation could hit 5.5% by Christmas.

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