Economists had expected retail sales to be flat in May after rising 0.9 per cent in April.
Sales continued a sustained period of year-on-year growth, with the volume of retail sales in May 2015 estimated to have increased by 4.6 per cent compared with May 2014.
This was the 26th consecutive month of year-on-year growth, the longest period of sustained growth since May 2008 when there were 31 periods of growth.
Garden centre sales in May were up seven per cent.
However, UK households were more downbeat about their finances in June, as signalled by the seasonally adjusted Markit Household Finance Index (HFI) falling from 45.5 in May to 43.8.
The latest reading was the lowest recorded so far in 2015, although it remained consistent with a relatively mild squeeze on household finances.
Negative financial perceptions were reported in all of the monitored job categories during June. The strain on finances was also broad-based at the regional level.