A drop in the value of fuel sales is blamed for a decrease in electronic card spending in November 2008.
Statistics New Zealand says there were 88 million electronic transactions that month with a value of $4.8 billion.
The agency says that's a decrease of 2.8% compared with October 2008 - the largest monthly drop since October 2002.
It says the main contributor was a substantial decrease in the value of fuel sales, as fuel prices continue to decline.
Retail card spending was down 2.3% in November 2008, compared with the previous month.
Core retail credit card purchases, which exclude motor vehicle-related industries, decreased by 0.5% in November, following an increase of 0.9% in October.
Electronic transaction figures for December 2008 will be issued on 22 January.