Head of sales and marketing for Paymark Paul Whiston said the past 14 days was a strong start and he tipped spending to grow with two big shopping weekends to come.
Greg Harford, general manager of public affairs for Retail NZ, said more stores were offering discounts and pre-Christmas sales to tempt people to open their wallets.
"That points to people not getting out and spending as much and the highly competitive global marketplace. Consumers have unprecedented choice in where they go, retailers are keen to offer the best deals possible."
Retail NZ has been running a campaign encouraging people to buy from local retailers, whether that is online or in person.
Harford said he was not surprised books were selling well as they make a tangible gift. Cookbooks, non-fiction and coffee table books have been particularly strong. Online retailer Mighty Ape said it had seen its biggest growth in sales of books and video.
"Evidently Kiwis still very much value the tactile - especially when it comes to giving gifts," said spokesman Dylan Bland.
Julia Bell, spokeswoman for The Warehouse, said Christmas shopping momentum was building.
"This year many have started their Christmas shopping, but most are yet to finish so we expect the next few days to get much busier as we approach the week of Christmas."
Paymark's figures were for the two weeks between November 29 and December 13.
They show that groceries and takeaways are also seeing big sales. Spending was up more than 9 per cent on the same time last year.
But it seems men are slower to go shopping - spending on clothing, apparel and jewellery was among the slowest with an increase of just 0.1 per cent.
Paymark, which deals with most transactions, processed 46.37 million, a 6.8 per cent increase on the same period last year.
Sun tipped to greet Santa
Barbecues, sunhats and strawberries on the lawn could be on the cards this Christmas Day.
After a topsy-turvy start to summer, forecasters are tentatively predicting we will be able to break out the beach gear and enjoy a sunny December 25.
"The last weekend before Christmas, we have a low pressure system crossing the country, but behind that is a high pressure system," Weather Watch.co.nz analyst Philip Duncan said.
"There will be a showery sou'wester in the days before Christmas and a high moving in." December's changeable weather wasn't over yet, Duncan said.
"We've one more burst of unsettled weather for the next 10 days," he said.
"Then around about Christmas time there's the chance of this high."
The MetService warns much of the North Island faces wet weather today and throughout the week.
It would not be drawn on any Christmas Day predictions.
