December has so far seen spending growth unseen for several years, Paymark says.
Spending for the first three weeks of December increased 6.9 per cent on the same period last year.
Paymark, which processes around three quarters of New Zealand's electronic transactions, said shoppers spent more than $3.5 billion on their eftpos cards during that period.
Last Friday was the busiest day of the year so far, with $235.6 million through the tills, up 5.7 per cent on the same day last year.
Paymark head of sales and marketing Paul Whiston said growth so far for December was ahead of the year-to-date average.
"The growth rates this December have been higher than we've experienced in a number of years.''
However, the annual growth rate slowed throughout December, which could indicate better planning, or shoppers relying on the next two days to get everything done, he said.
"Maybe tonight and tomorrow will be interesting to see if there's that last minute frenzy to get things.''
New Zealand Retailers Association chief executive John Albertson said the results were encouraging.
Anecdotal feedback from retailers suggested shoppers were feeling more positive, which meant they spent more, he said.
Today and tonight could see a "last big splurge'' before people headed on holiday tomorrow.
Popular items under the tree this year include some new shoes, a new pet, jewellery, electronic gadgetry and something for around the home.
VALUE OF SPENDING BY REGION ($ millions):