Shoppers spent $5.3 billion in December, up $300 million from the year before, the country's main network for electronic transactions says.
Paymark, which manages more than three-quarters of spending from EFTPOS and credit cards, released a summary of holiday spending which showed people spent more through its network on New Year's Eve than on Boxing Day.
Paymark processed $172m on the last day of 2014, which was up $12.2m from New Year's Eve 2013.
The company recorded 3,724,443 transactions on 31 December.
Paymark said it reached a significant milestone with its 13 billionth transaction, which happened two days after Christmas. Its 12 billionth transaction was recorded just 11 months earlier, at the end of January.
The company said this could be a reflection of huge growth in contactless transactions through its network.
Spending through Paymark includes GST paid to retailers and also includes any cash withdrawals when purchases are made.
Retail NZ spokesperson Greg Harford said Christmas had been positive for retailers overall.
"Anecdotally we've heard that the Christmas period has been fairly positive, so most retailers are pretty happy with the way it's gone.
"People were a bit nervous early on in the Christmas period but it's come right and as the weather's improved and people have got out and got shopping, things have come along nicely."
However, more money still would have been spent through overseas sites, Mr Harford said.
"One of the problems that retailers face is that if you are buying something from offshore and it's a low-value good, you don't have to pay GST and duty as it comes into the country, which means that retailers aren't playing on the same level playing field that we'd be hoping for."
The Government needed to close the loopholes around GST and overseas goods, he said.