The latest pick-up in total spending arrests three annual declines, though it's still at a subdued level and near a decade-low.
Tourism has struggled since the global financial crisis in 2008 eroded people's disposable income for big ticket holidays and the rising price of oil and strengthening New Zealand dollar dimmed the appeal of long-haul travel.
The government is hoping to attract an extra 200,000 visitor nights from a proposed Auckland convention centre.
The deal has sparked staunch opposition, as it would see casino operator SkyCity Entertainment Group foot the $350 million tab to build and operate the venue in exchange for an extension to its gaming licence, which would let it underwrite the expense with more pokie machines.
Some 300,000 business travellers spent $598 million in the year ended March 31, compared to the same number spending $616 million a year earlier.
About 1.22 million visited New Zealand for a holiday, the same number as a year earlier, and spent $2.95 billion, compared to $2.97 billion.