A Reuters poll of economists had pointed to a rise in inflation to 1.4%.
A jump in regulated electricity and gas bills and higher clothing prices helped to push inflation up.
Core inflation, which excludes energy prices and other volatile items, rose by 1.3% in the 12 months to April, the Office for National Statistics said.
The Bank of England says inflation in Britain is heading above its 2% target and will hit 2.5% at the end of 2021 thanks to a rise in global oil prices and the expiry in September of COVID emergency cuts to value-added tax in the hospitality sector, as well as comparisons with the COVID slump of 2020.
The BoE thinks inflation will then slip back to 2% in 2022 and 2023.