Shoppers spent a massive $5.3 billion last month, the latest Paymark figures show.
Spending last month - fuelled in part by Christmas shopping, Boxing Day sales, and New Year's Eve holidaymakers - was up $300 million, or 5.4 per cent, on December 2013.
Last year also saw the highest growth in spending since 2007, with Paymark processing $52.3 billion of transactions for the year - up 6.6 per cent on 2013.
Paymark customer relations head Mark Spicer said the high growth rate was due to stronger consumer confidence. "I think what we are seeing now is consumer confidence is stronger along with a building of a stronger economy. Consumers feel more confident about getting out there and spending and that's reflected in the figures."
Mr Spicer said spending throughout 2014 had been very consistent. However, spending had got off to a slow start in December - Paymark's busiest month of the year.
"There were some strong figures all the way through [2014], albeit December did start a bit slower, and I think that can be attributed to the cooler start to summer.
"But generally, by the end of that calendar year the figures have shown us it has been a very strong year, for both value and also for transaction and volume."
By the end of the December, Paymark recorded strong figures. Christmas Eve was its biggest day of the year, with Kiwis spending $263.5 million. Paymark also reached another milestone in December after its 13 billionth transaction was recorded on December 27 in Taupo.
The 12 billionth transaction was recorded in January 31, just 11 months beforehand. Mr Spicer said Paymark also noted strong and consistent growth in the accommodation, food and beverage sectors throughout 2014.
He said that could possibly be due to New Zealand being recognised as a "quality tourism destination".
The value of transactions last year was up by 11.6 per cent in the accommodation sector, and 11.2 per cent in the food and beverage sector, which included cafes, restaurants and bars, compared with 2013.
How much Kiwis spent in December 2014:
- New Zealand spending totalled $5.3 billion, up 5.4 per cent on $5.1 billion in December 2013.
- Auckland spending totalled $2.1 billion, up 5.9 per cent on $2 billion in December 2013.
- Bay of Plenty spending totalled $357.8 million, up 5.9 per cent on $337.8 million in December 2013.
- Wellington spending totalled $486.7 million, up 2.5 percent on $474.6 million in December 2013.
- Nelson spending totalled $112 million, up 8.2 per on $103 million in December 2013.- Canterbury spending totalled $603.3 million, up 5.2 per cent on $573.3 in December 2013.
- Otago spending totalled $294 million, up 8.5 per cent on $271 million in December 2013.
(Source: Paymark)