Consumer prices rose 2.9% in May.
The rate has been steadily increasing following a period of relatively low inflation in 2015 and is at its highest since April 2012.
Higher prices for recreational and cultural goods and services (particularly games, toys and hobbies) contributed most to the increased rate.
There were smaller upward contributions from increased electricity and food prices.
The index is worrying for many families because wages are rising more slowly than inflation and key benefits are capped.