"The figures were positively impacted by the Christmas rush - Christmas Eve alone was up 18.5 per cent, and Boxing Day was up 12 per cent - but there has been an emerging trend through the latter part of 2013 of higher spending rates."
The New Zealand Retailers Association said business has been flat, but "slightly improving", over the last five years.
But with the strong final quarter of 2013, and the busy Christmas trade, things are looking up, association spokesman Russell Sinclair said.
"I'm certain we've turned the corner and the retailers I spoke to pre-Christmas believed that there will be further gradual improvement in business in 2014," he said.
Pet shops, sporting and camping gear stores, footwear retailers, and jewellery stores all recorded 8-9 per cent increases on the previous December figures.
Double-digit year-on-year growth was seen in furniture stores and duty free shops.
New Zealanders and tourists were out and about catching up with friends and family around the country with the hospitality and accommodation sectors both enjoying spikes.
During 2013, Paymark processed 986 million transactions, totalling $49.3 billion.
The average transaction value of $49.99 was 0.2 per cent above the 2012 average.
"For the first time since the 2008 global financial crisis we're seeing a significant increase in spending which should bring optimism for most Kiwi retailers, and hopefully we see this momentum continue into 2014," said Mr Whiston.
BOOMING SECTORS FOR DECEMBER 2013, COMPARED TO 2012
* Duty free shops - up 17.3 per cent
* Furniture stores - up 11.5 per cent
* Accommodation - up 11.1 per cent
* Hospitality sector - up 9.5 per cent
* Sporting/camping equipment stores - up 9.3 per cent
* Pet stores - up 9.2 per cent
* Footwear retailers - up 9.2 per cent
* Watch/jewellery shops - 8.7 per cent