The Office for National Statistics said the annual rate is the lowest since November 2009 when it was 1.9%.
The largest downward pressures to the change in CPI annual inflation between April and May came from motor fuels and food & non-alcoholic beverages while the largest upward pressures to the change in CPI annual inflation between April and May came from air and sea transport, where the timing of Easter had a significant impact on the April to May movement.
Retail prices index annual inflation stands at 3.1% in May, down from 3.5% in April - the lowest since December 2009.
Vicky Redwood, chief UK economist at Capital Economics, said: “The further fall in UK inflation in May is a nice surprise, given that we and the consensus had expected it to hold broadly steady.
“Admittedly, core inflation nudged up from 2.1% to 2.2% but this mainly reflects a brief period of sharp discounting this time last year and we had thought it would pick up more sharply than this.
“Headline inflation will probably stay around this level in June, but it should then start to fall more quickly and we still think it could be below 2%before the end of the year.”
