Paymark's latest data shows spending in December was up almost eight percent.
The figures show that $5.5 billion was spent last month, during retail's busiest time of the year.
Spending in Bay of Plenty was up ten percent on the same period last year, while Marlborough, Auckland, Northland and Southland also saw strong growth.
Retail NZ general manager Greg Harford said the Reserve Bank cutting the official cash rate to 2.5 percent and lower petrol prices could be contributing factors to the increase in spending
Mr Harford said the spending increase showed consumers were feeling more confident about 2016.