"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):