A combination of three national holidays, and five Sundays and Mondays in April saw spending decline for the first time since October 2009, latest figures show.
Paymark, which processes about 75 per cent of all electronic transactions in New Zealand, said it processed nearly $3.7 billion worth of transactions during April, a dip of 0.3 per cent in comparison to April 2011.
Kiwis experienced a "go-slow in retail spending" this month, said Paul Whiston, Paymark head of sales and marketing.
"April contained five Sundays and Mondays, which are the two slowest spending days during the week, as well as Good Friday, Easter Sunday and Anzac Day, which are three of the four slowest shopping days in the year."
While the underlying trend of modest spending growth remained, the main factor was the holiday effects in April, Whiston said.