Shoppers have spent almost $4 billion on their cards so far this month.
According to the payments provider, Paymark, that was $170 million more than this time last year.
It described Christmas spending as steady, saying a late start to summer and lower fuel prices may be factors in the overall spend.
Paymark said an increasing number of retailers were starting their Boxing Day sales before Christmas, which was boosting the number of transactions, but the value may be slightly lower.
Head of customer relations Mark Spicers said says the Auckland, Nelson and Otago regions are the strongest spenders, while Southland and South Canterbury are trailing behind the rest of the pack.
He said Paymark does not know what specific items people are buying, but the categories of electronic goods, watches and jewellery are popular.
Mr Spicer said more people would be hitting the shops for last minute items now the window to complete online shopping before Christmas had closed.