Official data showed sales volumes last month were 1.2% lower than in June.
Food stores sales volumes fell by a monthly 2.6% while non-food stores sales volumes fell by 1.7%.
However, July's data represented only the second time that sales volumes fell on a month-to-month basis so far in 2023, suggesting resilience in consumer demand.
Market research firm GfK reported last month that consumer confidence fell in July for the first time since January.
Retail sales volumes were 3.2% lower than a year earlier, the ONS said, compared with economists' forecasts for a 2.1% decline.
Persons:
Sterling, Heather Bovill, Ruth Gregory, GfK, Samuel Tombs, BoE, Tombs, Spencer, James Davey, Kate Holton, Susan Fenton
Organizations:
Reuters, Office, National Statistics, Department, Bank of England, Capital Economics, Macroeconomics, Thomson