Electronic card transactions last month pointed to continued recovery in retail spending, but economists said turmoil in financial markets imparted a "that was then, this is now" quality to the data.
Retail purchases charged to debit, credit or charge cards rose 0.4 per cent, on top of a 1.1 per cent increase in June.
Excluding petrol stations and caryards the increase was 0.5 per cent, on top of a 2.1 per cent rise in June.
Fuel sales were down 1.4 per cent, the third monthly decline in a row.
"While this in part may be related to drivers reacting to high prices, we believe it is more likely to be a reflection of the recent drop in retail petrol prices," Goldman Sachs economist Philip Borkin said.