Spending using electronic cards is up due to higher fuel prices.
Official figures on electronic card transactions, which include debit, credit and charge cards, shows retail spending rose a seasonally adjusted 3% in August, the biggest increase in nearly a decade.
Spending on fuel had its biggest monthly rise since the series began in 2002, rising by more than 10%, due to higher petrol and diesel prices.
Excluding fuel and car sales, core retail spending rose 1%, led by clothing, and bars and restaurants, and accommodation.
But ASB economist Christina Leung says a patchy labour market and a continued focus on repaying debt is likely to restrain spending growth.
The survey covers about 65% of retail sales.