Photo: RNZ
New Zealand needs a system to ensure that tax brackets are regularly updated in line with inflation, so that we do not go another decade without change, tax commentators say.
The government announced in this year's Budget that tax brackets will move higher as of 31 July.
The change will mean a reduction in tax for everyone earning more than $14,000.
It is the first bracket shift since 2011, and since then, the impact of wage growth and inflation has pushed more people into higher tax brackets.
As a proportion of total household income, the income tax paid by individuals had increased from 15.39 percent in 2012 to 18.8 percent in 2022 because even income increases that were only keeping pace with the rising cost of living resulted in higher tax bills.
NZ Initiative chief economist Eric Crampton said failing to adjust the thresholds since 2011 had pulled about a million people into the 17.5 percent tax band who should have been in the lowest, 10.5 percent, using the methodology of when the bands were set.
In 2012, the most common annual wage was about $40,000 but it has since shifted to near $70,000.
The minimum wage of $23.15 an hour equates to an annual salary of just over $48,152 for someone on a 40-hour week.
In the current tax bands, that would put those workers on the cusp of the second tax bracket.
After the changes, it puts them just below - the 17.5 percent rate will kick in at $15,601.
"You should be on the lowest tax rate, definitely, if you're on minimum or close to minimum wage," said Deloitte tax partner Robyn Walker.
"You move quickly through those lower bands and suddenly you're earning $78,1000 and on a 33 percent tax rate. The rates kick in very low, I think, compared to some other countries."
Tax expert Terry Baucher said there had only been five or six adjustments to the tax bands since the late 1980s.
He said other countries, such as Britain, had mandated inflation indexation so the government had to statutorily override the change if it wanted to keep tax bands the same when inflation rose.
"It's a deliberate political choice here. Politicians feel they can do that, they haven't been challenged about it. But sooner or later, as has happened here, one of the parties runs into a hole where they have to make a change, the timing is not right but they have to do it because it's been so long."
He said it was a way that government revenue and spending could increase "by stealth".
"There's a certain lack of accountability and oversight once they are in charge."
Walker said tax rates were very political.
"It would be good if all the parties had some sort of commitment to a policy of indexation - whether they can agree on what that should be and how often it should be done, should it be triggered based on time passed o r the amount of inflation and so on, there are a lot of questions."