The Inland Revenue Department (IRD) says they will be keeping a "close watch" on high income workers who may try and avoid the new tax rate.
The Labour Party introduced a new tax rate of 39 percent on income over $180,000, which will take effect on April 1 2021.
IRD will be keeping a "close watch" for any activity by people who try to avoid the 39 percent rate, Customer Segment Leader Tony Morris says.
"If that's how it looks to us then we'll take the necessary action.
"We're currently talking directly to tax agents and putting out a range of direct communications that are effectively a warning message and a guide to what kinds of activity will concern us."
Morris says IRD has already published several statements covering income tax avoidance, all of which were available on their website.
"We're about to reissue one of those, a Revenue Alert first put out there in 2011," he says.
"It focuses on diverting income from one business entity to another, and while we haven't substantially changed our approach to this, it reframes the alert in the new context of the new 39 percent rate."
Morris says customers should think carefully about the moves they make around the new rate.
"The message really is, if you're in doubt, or have questions, the best thing to do is seek advice. And of course, you can seek rulings from Inland Revenue."
New Zealand individual tax rates (effective April 1, 2021)
- 10.5 percent on income earned between $0 and $14,000
- 17.5 percent on income earned between $14,000 and $48,000
- 30 percent on income earned between $48,000 and 70,000
- 33 percent on income earned between $70,000 and $180,000
- 39 percent on income earned over $180,000