Early figures suggest many shoppers held off their Christmas spending until the Boxing Day sales.
Paul Whiston from the country's largest eftpos company, Paymark, says unofficial data shows this year's Boxing Day turnover may be higher than last year's.
Mr Whiston says at the peak of shopping between midday and 3pm, 220,000 purchases were made. He says the activity peaked at 69 transactions per second.
Major shopping centres around the country reported a brisk trade for the day, with many shoppers taking the opportunity to redeem gift vouchers in the sales. There were even queues at some malls before doors were opened on Friday morning.
The Westfield group, which operates 12 shopping centres around the country, said all its malls were extremely busy.
The country's largest shopping mall, Sylvia Park in Auckland, was expecting 100,000 people to have come through by the end of the day's trading.