Figures from electronic transaction provider Paymark show retailers enjoyed a sales boom on Boxing Day.
Paymark, which processes 75% of all transactions, says spending on Thursday was up 13.4% on Boxing Day last year.
It says $120 million passed through the network, with the biggest increase in electronic retail, where sales were up 31.7% on last year.
A lot of money was also spent on clothing and jewellery.
Paymark's head of sales and marketing, Paul Whiston, says one reason for the sales boom is that bad weather turned people away from the beach and into the malls.
He says some people also held back their Christmas spending in anticipation for Boxing Day deals.
