Paymark said people were getting ready for the traditional summer road-trip, with sales at tyre stores up 12.4 per cent.
Phil Deason of Paymark said the company was optimistic for a good finish to the year.
"At this time last year we saw that Kiwis started the first days of December with a shopping blitz, then things fizzled out a bit over the next week or so," Deason said. "The figures we've had ... show that things are a bit more consistent than last year. "
On Sunday December 11 Kiwis spent $117.5 million through Paymark terminals, an increase of $6.7 million, or 6 per cent, on the same day last year.
Albertson said New Zealanders had a "tradition" of leaving their Christmas shopping to the last minute, so it was a good sign that spending had been so strong during the first half of this month.
And having Christmas Eve on a Saturday this year was also positive, he said. "I think it will be a very big [shopping] day."
John Journee, chief executive of Noel Leeming Group, which operates Noel Leeming and Bond and Bond stores, said sales across the group were up about 9 per cent in the first half of December, compared with the same period last year.
Small appliances, such as mixers, blenders and espresso machines, as well as smartphones, e-readers and televisions, were proving popular, Journee said.
He said the lift in consumer spending this Christmas was a positive sign after the "bleak" trading of the past two Christmases.
But shoppers were still showing restraint. "It's certainly not exuberant spending."
Terry Cornelius, executive director of Auckland's Smith & Caughey's, said sales this month were well up on last year.
About 5000 children had passed through the "Santa's enchanted forest" at its Queen St store, he said. "Last year [shopping] was almost a chore to a lot of people, but this year they're out to enjoy the experience of shopping and enjoying Christmas."
Pumpkin Patch chief financial officer Matthew Washington said festive season trading had started "reasonably well" at the listed children's clothing retailer's stores on both sides of the Tasman.
"And we also get an extra Saturday this year, which is Christmas Eve, so it will be interesting to see how that plays out."
Rod Duke, managing director of Briscoe Group, which operates Briscoes, Rebel Sport and Living & Giving stores, said last week's rain had affected sales of outdoor items such as sports equipment and outdoor furniture.
"But to be fair I'd have to say that so far ... [business] is pretty good," Duke said. "We've had a very good November and December ... but so much depends on the last week up to Christmas and Boxing Day."