Tax Bracket Creep: The Hidden Tax on Your Pay Rise

The government adjusted your tax brackets. They just didn't adjust them enough.

In July 2024, the National-led government shifted New Zealand's personal income tax thresholds for the first time in 14 years (if you don't count the addition of the 39% top rate in 2021, which was an increase, not relief). It was presented as meaningful tax relief. And to be fair, most workers are better off than they were.

But here's the part nobody made a fuss about: cumulative CPI inflation since the last real bracket adjustment in 2010 sits at roughly 44%. The 2024 changes moved thresholds up by approximately 11% to 14%, depending on the bracket. The government closed about a quarter of the gap. The rest is still quietly delivering extra revenue to the Crown.

This is bracket creep, and it remains one of the most effective stealth taxes in New Zealand.

At a glance: New Zealand's income tax thresholds were adjusted in July 2024 for the first time since 2010. But cumulative inflation over those 14 years was roughly 44%, while the thresholds moved by only 11% to 14%. For a worker on $75,000, the remaining gap costs approximately $2,272 per year in additional tax. There is no automatic indexation mechanism to prevent the gap from widening further.

What Is New Zealand Tax Bracket Creep?

Bracket creep occurs when inflation pushes incomes into higher tax brackets without any real increase in purchasing power. Your pay goes up, the cost of everything goes up alongside it, but the tax thresholds sitting between you and a higher marginal rate barely move.

Famous economist Milton Friedman put it simply:

"Inflation is the one form of taxation that can be imposed without legislation."

In New Zealand, tax brackets are not automatically indexed to inflation. They only move when Parliament decides to move them. And Parliament, historically, has found the extra revenue rather convenient.

New Zealand's Current Tax Brackets

For the 2025/2026 tax year (1 April 2025 to 31 March 2026), the personal income tax rates are:

• $0 to $15,600 at 10.5%
• $15,601 to $53,500 at 17.5%
• $53,501 to $78,100 at 30%
• $78,101 to $180,000 at 33%
• $180,001 and above at 39%

These thresholds replaced the brackets set in October 2010, which were:

• $0 to $14,000 at 10.5%
• $14,001 to $48,000 at 17.5%
• $48,001 to $70,000 at 30%
• $70,001 to $180,000 at 33%
• $180,001 and above at 39%

The rates didn't change. The thresholds simply moved upward. But not nearly far enough.

New Zealand's Gap Between Adjusted and Inflation-Indexed

If the 2010 thresholds had been indexed to cumulative CPI inflation of approximately 44%, here is roughly where they would sit today:

• 10.5% bracket ceiling: approximately $20,160 (actual: $15,600)
• 17.5% bracket ceiling: approximately $69,120 (actual: $53,500)
• 30% bracket ceiling: approximately $100,800 (actual: $78,100)
• 33% bracket ceiling: approximately $259,200 (actual: $180,000)

The bottom bracket was adjusted by $1,600 when a full inflation correction would have been closer to $6,160. The 30% bracket ceiling moved from $70,000 to $78,100 when it should sit above $100,000. And the $180,000 threshold for the top rate hasn't moved a cent.

Worked Examples: Where Bracket Creep Bites

The minimum wage worker. The adult minimum wage is currently $23.50 per hour (rising to $23.95 from April 2026). A full-time worker doing 40 hours per week earns $48,880 per year. Under today's brackets, every dollar of this income falls within the first two brackets (10.5% and 17.5%), producing a total tax bill of $7,462 and an effective rate of 15.3%.

Before the 2024 adjustment, the same income would have crossed into the 30% bracket at $48,001. So the threshold change did solve the most egregious problem for minimum wage workers on standard hours. Credit where it's due.

But pick up five extra hours per week (45 hours total) and annual income rises to $54,990. Under current brackets, $1,490 of income suddenly lands in the 30% band. Under fully inflation-adjusted brackets, the 30% rate wouldn't kick in until above $69,000, and every dollar of the $54,990 would remain within the first two brackets. The overtime penalty is real, and it falls hardest on people who can least afford it.

The $75,000 professional. This is where bracket creep really shows its teeth. At $75,000, a worker pays $14,721 in tax under current brackets (effective rate: 19.6%). Under fully inflation-adjusted brackets, their entire income would sit below the 30% threshold, and they'd owe $12,449. The annual difference: $2,272 in additional tax, for zero change in what their salary actually buys.

The $90,000 earner. At $90,000, income crosses into the 33% band under current brackets, producing a tax bill of $19,578 (effective rate: 21.8%). If brackets had been properly indexed since 2010, the 33% rate wouldn't begin until above $100,800. The total bill under indexed brackets: $16,949 (the difference comes from more income being taxed at 17.5% and 30% rather than 30% and 33%). The annual bracket creep penalty: $2,629.

Why This Matters More Than Most People Realise

The New Zealand Initiative, a Wellington-based think tank, highlighted the scale of the problem. Before the 2024 adjustment, the failure to index thresholds since 2010 had pushed an estimated 40,000 people from the 10.5% bracket into the 17.5% bracket, around 187,000 people from 17.5% into the 30% bracket, and 161,000 people from 30% into 33%. In total, bracket creep was generating an estimated $1.3 billion per year in additional tax revenue, none of it legislated.

The 2024 adjustment reduced this, but it did not eliminate it. The core problem remains: there is no automatic indexation mechanism in New Zealand's tax system.

Selective Indexation

Here is the part worth noticing.

NZ Superannuation (the pension) is adjusted annually for inflation. Benefits paid through Work and Income are adjusted annually. Even child support payments are inflation-adjusted each year. It turns out the government is perfectly capable of indexing things to inflation. It just prefers to do so when the adjustment means the Crown pays more, not when it means the Crown collects less.

But the tax brackets applied to your income? Only when a government decides it is politically convenient. Which, between 2010 and 2024, was never.

The Crown's Tax Take

For context, core Crown tax revenue for the year ended June 2024 was $120.6 billion, up $8.2 billion from the prior year. Treasury attributed $3 billion of the PAYE growth specifically to wage growth pushing people into higher brackets. Total Crown revenue for the year to June 2025 reached $169.8 billion.

Compare this trajectory with the figures from just a few years prior: $97.4 billion in 2021, $107.9 billion in 2022, and $112.4 billion in 2023. The tax take has grown significantly faster than inflation. Bracket creep is not the only driver, but it is a persistent and largely invisible one.

Can You Do Anything About It?

Bracket creep is a policy-level problem. You cannot individually negotiate your way around it. But you can make informed decisions knowing it exists.

Understand your marginal rate. If your income sits near a bracket boundary, even modest pay rises, bonuses, or overtime hours can push a portion of your earnings into a higher rate. This doesn't mean you should refuse a pay rise (please don't), but it does mean the after-tax benefit may be smaller than the headline number suggests.

Maximise available credits. The Independent Earner Tax Credit (IETC) now covers individuals earning between $24,000 and $70,000 per year, providing up to $520 annually. Many eligible workers don't claim it. Check your tax code is correct. If you're eligible, an ME code ensures the credit is applied automatically.

Think about the bigger picture. If bracket creep is quietly reducing your purchasing power each year, the most effective personal response is to grow your wealth faster than the tax system can erode it. Building a diversified investment portfolio is one of the few individual actions compounding in your favour over time, rather than against you.

Review your KiwiSaver Scheme settings. From April 2026, the default KiwiSaver contribution rate rises to 3.5%. If you're already in a higher bracket than you expected, it is worth reviewing whether your contribution rate and Scheme selection are working as hard as they should.

What About Indexation?

Most OECD countries with progressive tax systems build in some form of automatic adjustment. The International Monetary Fund has long noted the corrosive effects of inflation on tax systems without indexation. Australia periodically adjusts its brackets (though it has had its own bracket creep controversies). The United States indexes its brackets to the Consumer Price Index annually.

New Zealand does neither. There is no legislative mechanism requiring Parliament to review or adjust tax thresholds at regular intervals. Every adjustment requires an active policy decision, which means every year without one is effectively a silent tax increase.

The New Zealand Initiative has argued for automatic annual indexation once accumulated inflation warrants bumping a threshold up by $1,000. The logic is simple: if a government wants to increase taxes, it should have to say so openly and legislate for it, rather than simply waiting for inflation to do the work.

It is hard to disagree with the principle. Whether you believe in lower taxes, higher taxes, or something in between, the method should at least be transparent.

The Bottom Line: Tax Bracket Creep In New Zealand

For anyone earning a salary in New Zealand, bracket creep will continue to chip away at purchasing power for as long as thresholds remain static and unindexed. Unless automatic indexation becomes law, each year without an adjustment is another quiet pay cut dressed up as nothing happening at all.

If your financial position deserves more attention than it's getting, a conversation with a qualified financial adviser might be the most productive hour you spend this month. Not because anyone can fix bracket creep for you, but because the best response to a system tilted against your purchasing power is to make sure every other part of your financial life is working as hard as possible.

Frequently Asked Questions

What is bracket creep?

Bracket creep occurs when inflation pushes incomes into higher tax brackets without any real increase in purchasing power. The result is a higher tax bill for the same standard of living.

Were NZ tax brackets changed in 2024?

Yes. From 31 July 2024, thresholds were increased as part of Budget 2024. However, the adjustment covered only about a quarter of the cumulative inflation since the last full change in 2010.

Does New Zealand index tax brackets to inflation?

No. Unlike the United States, New Zealand has no automatic mechanism for adjusting brackets. Each change requires a specific government decision.

Does bracket creep affect people with second jobs?

Yes, and it can be particularly painful. Secondary tax codes are based on the bracket your combined income falls into. If bracket creep has pushed your total earnings into a higher band, the withholding rate on your second job increases accordingly. Check your secondary tax code aligns with your actual combined income to avoid overpaying or underpaying.

What can I do about bracket creep?

At an individual level, very little. Bracket creep requires policy change. What you can do is ensure your tax code is correct, claim credits you're entitled to (like the IETC), and focus on growing your wealth through saving and investing to outpace the erosion.