New figures indicate shoppers are keeping their credit cards in their pockets despite a forthcoming rise in GST on 1 October.
Statistics New Zealand says retail spending using electronic cards eased for the second consecutive month in August.
Retail spending using cards fell 0.2% in August, following a fall of 0.1% in July.
Spending on big-ticket durable goods fell 0.6% following two months of rises. Food purchases also fell, although economists attributed the drop to lower prices in August.
Money spent using credit cards fell to 42.6% of card transactions from 43.2% a year ago.
Figures for total spending at shops in August will be issued later in September.
Radio New Zealand's economics correspondent says it is likely to be another lacklustre month, as money spent using electronic cards accounts for 60% of all spending
Figures issued on Tuesday showed spending at shops in July fell 0.4%, the biggest fall in five months.
Pick-up not expected until 2011
The Retailers Association says it expects retail sales to stay in the doldrums until well into next year.
A spokesperson, Barry Hellberg, says in the wake of the credit crunch people are being much more careful with their spending.
Mr Helberg says many people also face rising costs, such as higher interest rates, and that has also dampened spending.
Many people will get tax cuts on 1 October, but that will be off-set by the planned rise in GST, he says.
Deutsche Bank chief economist Darren Gibbs says it is not surprising spending on credit and debit cards remained sluggish in August.
Mr Gibbs says there may be a rebound in spending on big ticket items in the lead-up to the GST increase but, overall, consumers remain cautious about opening their wallets too wide.
Total electronic card transactions, which include travel, health and wholesaling, rose 0.1%.