And the New Zealand Institute of Economic Research's quarterly survey of business opinion showed retailers remained pessimistic as rising costs that they weren't able to pass on squeezed profitability.
Westpac Banking Corp senior economist Satish Ranchhod said he expects retail spending to continue rising, but at a more moderate pace.
"While spending is now being supported by the government's Families Package, disposable income growth still remains fairly modest," he said.
"In addition, many households are finding their spending power is being crimped by rising costs for necessities like fuel."
Today's data show actual spending on electronic cards rose to $6.92 billion in September, up 4.9 per cent from a year earlier. Of that, core retail spending was up 5.1 per cent to $4.39b. Spending on petrol jumped 11 per cent to $640 million and hospitality spending rose 7.3 per cent to $997m.
Credit cards were more popular than debit cards, accounting for 52.3 per cent of 143 million transactions, compared to 49.3 per cent of 137 million transactions in September last year. The value per transaction was $48, unchanged from a year earlier.
Reserve Bank data show total credit cards billings in New Zealand rose an annual 7.7 per cent to $3.73b in August while total advances outstanding was up 5.9 per cent at $7.17b.