"Low unemployment in Northland means more work so people can afford to buy. There's also a lot more certainty around people maintaining their jobs which is positive," said the business leader.
Collins said the construction industry was also doing well as were tourism operators.
"It shows there's still a place for the traditional retail sector in a business environment. But a big part of that sector is the quality of service and also a need to try new products."
Tourism New Zealand's strategy in recognising areas such as Northland with spare accommodation capacity also helped in growing retail spending, he said.
Retail spending in the four broad sectors in 2012 was $2.1b, $2.21b in 2013, $2.29b in 2014, $2.42b in 2015 and $2.6b a year later.
The spending per person in Northland also went up during that period— from $13,170 in 2012 to $15,639 last year.
Northland tourism leader Jeroen Jongejans said unlike in the past, people now were prepared to pay for a quality product.
A growing tourism market with five million international visitors to New Zealand predicted by 2023 would benefit Northland in terms of retail spend, he said.
Jongejans said with Auckland's economy growing for the last six to seven years, visitors from New Zealand's largest city contributed greatly to retail spending in Northland last year.
"All in all, I am not surprised spending is up. Northland is getting more attractive as Auckland is getting harder to live in and with better connectivity, people find it easier to set up businesses in Northland," he said.
Nationally, retail spend in 2017 was $92b — up 6.8 per cent from the previous year.
Stats NZ said while unsurprisingly most of the retail sales were in regions with high population such as Auckland, regional sales on a per capita basis favoured places like Northland.
"Regions with lower per capita retail spending tend to have lower median incomes, and a higher proportion of their retail spending goes to supermarkets and specialised food retailers, such as butcheries, delis and liquor stores.
"Regions with higher per capita retail spends tend to have higher average incomes, and a greater proportion of their retail sales are from the accommodation and food services industry group, largely driven by tourists."