UK Consumer Prices Index (CPI) inflation rose to 3.8% in July, up from 3.6% in June, surpassing most economists' forecasts of 3.7%.
Transport was the main contributor to the inflation increase, primarily driven by a 30.2% surge in air fares between June and July, the largest monthly rise since 2001.
Petrol and diesel prices also increased in July, contrasting with a decline during the same period last year.
Food and drink inflation continued its upward trend for the fourth consecutive month, reaching 4.9% in July from 4.5% in June.
Chancellor Rachel Reeves acknowledged that further measures are required to alleviate the cost of living pressures on households.