Paymark sales and marketing head Paul Whiston said Christmas Eve was Paymark's biggest day on record, with $238.4 million going through the network - a ''whopping'' 18.5% up on the same day in 2012.
Nationally, $134.4 million was spent on Boxing Day, up 12%.
''Christmas Eve this year smashed all our records. Not only did we see the highest value through the network ever, we also saw the highest number of transactions [at 4.35 million] and the largest number of transactions per second.
''To come off the back of a high like this and to also see the busiest Boxing Day that we've ever seen is a hugely positive result for retailers,'' he said.
The majority of the country's spending was in the Auckland-Northland region, with $90.8 million going through the system on Christmas Eve (up 19.8% from 2012) and $56 million on Boxing Day (up 13.2% from 2012).
Significant increases were recorded on Christmas Eve and Boxing Day in Canterbury (17%/15.1%), Wellington (12.9%/9%), and Waikato (18.7%/10.6%).
Otago spending was up 7.4% to $12.5 million on Christmas Eve, and up 7% to $7.5 million on Boxing Day.
Otago Chamber of Commerce chief executive John Christie said it was a significant increase in spending for the region, and believed it was an indication consumer confidence was high due to the improved economy.
''It shows Otago residents are confident in their employment prospects and their earning potential in the year ahead.
''Consumer confidence is growing again. It bodes well for our retailers.
''Also, what goes around, comes around - when retailers are happy [with their financial situation], they employ more people.''
Mr Whiston said Gisborne had the highest growth on Christmas Eve, up almost 36% on the previous year, and Wairarapa had an extra $200,000 injected into its local economy, an increase of 17.2% on 2012.
On Christmas Eve, spending at food/liquor retailers increased 28% and department stores increased 23.2%, he said.
For Boxing Day, it was the sales which had increases of 16.5% at clothing and jewellery stores, 16.6% at appliance and whiteware stores, 12% at electronics retailers, and 17.5% at floor covering and furniture stores.
Sporting and camping equipment outlets also had big days, both on Christmas Eve and Boxing Day, up 20.2% and 31.8% respectively.
More than 74,000 merchants and 116,000 terminals are connected to the Paymark network, which processes more than 75% of all electronic transactions in the New Zealand retail market.
