The Best Money Advice New Zealanders Swear By - 10 Rules That Work

Our guide to the personal finance advice that survives contact with real life - ten rules everyday New Zealanders consistently say made the difference, with the numbers that prove why.

10 Best Money Advice New Zealanders Swear By

Updated 31 July 2026

Summary

We've compiled this list from readers' emails, external research and the collective wisdom of New Zealand's online money communities, including r/PersonalFinanceNZ.
Our focus is simple but effective rules for managing money - each one checked against the evidence and costed in dollar terms, so you can see what following it is worth.
The purpose is practical - reflect on where you stand, pick the two or three rules that fit your life, and act on them - most take minutes to set up and pay off for decades.

Warning: These rules are proven starting points - we have not published personalised financial advice. This means:

Before acting on anything involving your mortgage, insurance or investments, consider and verify the details for your situation.
For example, cancelling insurance before new cover is confirmed can leave you exposed and the right investment mix always depends on your timeframe and goals.

Important: Before doing anything, get a basic emergency fund in place

Every rule below works better - and some only work at all - if you have cash for emergencies.
Three to six months of essential expenses in a on-call savings account is the least exciting money move you'll ever make and the foundation everything else stands on.
An emergency fund helps turn a redundancy into a financially manageable inconvenience and a car repair into a bad week instead of a 20% p.a.+ credit card balance.
It also protects your investments - people without a cash buffer are the ones forced to sell at the bottom of a downturn because life demanded money at the worst moment.
Our view is simple - even if you're starting from zero, start anyway. Our guide to emergency funds explains how even $1,000 stops most emergencies becoming debt and how you're better off financially.

10 Rules That Work (And Are Worth Considering)

Buy less house than the bank offers you

Our View: The single biggest financial decision most New Zealanders ever make is made once, signs them up for decades, and is routinely decided by "what will the bank lend us?"

However, we believe the bank's maximum should not be a target because the additional principal and interest costs over 20+ years add up considerably.

For example, a "nicer" house may cost an extra $400,000 - this means $2,398 of additional monthly repayments (assuming 6% p.a. over 30 years), a total cost of $863,353, which includes interest repayments of $463,353.

Not only are there costs with interest, but there are also higher bills for rates, insurance, and maintenance because bigger houses cost more to run, not just to buy.

With New Zealand house prices slumped in most areas, we suggest considering your needs if you're looking to buy a first home or upgrade. New Zealanders who buy a home that leaves room for an actual life have flexibility and are more financially robust.

Repay all high-interest debt before you invest a dollar

Our View: New Zealand has too much credit card debt and personal loans outstanding. We believe that paying off a 20% p.a. credit card is a guaranteed, tax-free, risk-free 20% return.

Before signing up to invest, thinking long about clearing any consumer-finance-related debts (e.g. credit cards, store cards, personal loans, BNPL and high-interest car finance) is a smart starting point. Only a mortgage, with its far lower annual interest rate, earns the right to coexist with your investing.

Time in the market beats timing the market

Our View: Nobody reliably picks tops and bottoms - the people who try mostly end up buying high and selling low. Starting to invest matters far more than starting perfectly - our guide to dollar cost averaging is a useful starting point for building long-term wealth by consistently investing.

For example, two people invest $200 a month, returning an average of 7% p.a. net of tax and fees. One starts at 25; the other waits until 35 for the "right time". At 65, the early starter has $524,963, and the waiter has $243,994 - the decade of dithering cost $280,968, which is more than the waiter's entire final balance.

Important: The amounts don't need to be big either - even $100 a month at 7% p.a. net of fees and tax becomes roughly $122,000 in 30 years. It has never been cheaper to invest - low-fee options like Kernel, Tiger Brokers and Simplicity make it easy.

Never borrow for things that lose value

Our View: Debt is legitimate if it's used to buy assets that hold or grow value, such as a house to live in. However, borrowing for things that shrink (expensive cars, furniture, phones, holidays, anything on buy-now-pay-later) means paying interest on top of depreciation, a guaranteed double loss.

A financed vehicle at double-digit interest rates loses value faster than you repay it, which is how people end up owing more than the car is worth. We understand that many cars are financed because drivers don't have the full amount upfront. However, car finance works best when the vehicle is affordable, depreciates slowly, and the interest rate is below 10% p.a.

Use the 10-week rule on everything you want

Our View: This is a brilliantly simple system for anyone with impulse-spending tendencies, although it's easier said than done.

It works like this:

When you want something, set up a transfer of 10% of its price into a separate account each week.
After ten weeks, you have the full amount - buy it guilt-free, or keep the money if the wanting has worn off.
Most of the time, people don't buy it. The majority of wants are hype with a two-week half-life.

Insure the catastrophes, self-insure the small stuff

Our View: Insurance exists for the events that would be financially problematic, not the ones that would annoy you. That means taking into consideration income protection if people depend on your pay, life cover if they depend on your existence, house insurance, car insurance and, for many, pet insurance.

One catastrophe New Zealanders consistently under-insure is serious illness. Our public system is excellent at emergencies, but our medicines funding lags most of the developed world, and modern non-funded cancer treatments can run to six figures. Non-Pharmac cover typically adds only a few dollars a week to health insurance - the definition of a catastrophe worth insuring.

Too many New Zealanders are generally under-insured but overpay or over-insure on some cover - we suggest reviewing your current costs policy by policy and making sure you're covered appropriately. And, for the small stuff, consider taking higher excesses to cut premiums and skip extended warranties which may not always be valuable.

Get on the same page as your partner

Our View: Who you build your life with is a bigger financial decision than any investment, and alignment matters more than either person's income.

Opposite money personalities are the norm, not a problem - a saver and a spender can thrive together with shared visibility of where the money goes, an agreed plan, and a regular time to talk about it before tension builds.

Our guides to bailing out partners financially and contracting-out agreements offer insights into what can be the most expensive experience of your life.

Bank half of every pay rise

Our View: Lifestyle creep is how $80,000 households and $180,000 households end up equally broke - every raise gets absorbed by upgrades that feel deserved and become invisible.

The solution is not idealistic - the moment any pay rise lands, redirect half of it to savings or investments by automatic payment, before you ever feel it in the account. You still get richer with every raise - your lifestyle improves, and your savings rate climbs - without the deprivation that makes budgets fail. It's the savings strategy that gets easier as life goes on.

Index funds beat clever share picks

Our View: The evidence is overwhelming, and two decades of New Zealand investor experience agrees - low-cost, broadly diversified index funds beat the vast majority of actively managed funds, individual share-picking and market-predicting over time.

Keep fees low (well under 0.30% a year), diversify globally rather than betting it all on a handful of local companies, and then do the hard part: nothing.

Know This: Markets will fall 10-30% several times in your investing life - the investors who get hurt aren't the ones holding through the fall; they're the ones who panic-sell into it and buy back after the recovery.

Decide now, while nothing is on fire, that when markets fall you'll keep your contributions running and won't sell. That single pre-commitment is worth more than any fund selection.

Delete the apps that exist to sell to you

Our View: This is the most self-aware advice ordinary New Zealanders give, and the one no finance textbook mentions - your spending problem might actually be an exposure problem.

Social feeds are the most sophisticated wanting-machines ever built, with hundreds of daily impressions engineered to convert contentment into cravings and make everyone else's lifestyle look like the baseline. You can't out-discipline an algorithm designed by thousands of engineers, so don't try.

Our suggestion: Delete the shopping and social apps, unfollow the accounts that make you feel behind, and unsubscribe from the sale emails. The time to purge is now - spenders who've done it explain that the wanting quietly stops because you can't crave what you never see.

Frequently Asked Questions

If I could only follow one rule, which one?

Rule 3 - time in the market - because it compounds hardest and forgives the most mistakes. If you don't have an emergency fund yet, that comes first, as it's what makes every other rule survivable. Whichever rule you choose, make it automatic.

Does the small stuff really matter, or should I just earn more?

We suggest factoring both - the big levers - housing (rule 1), debt (rule 2) and your income - move your finances the most, and one successful job change can outdo years of small savings. But unexamined spending defaults still leak thousands a year, and a higher income without rule 8's discipline reliably becomes higher spending. The pattern among New Zealanders who get ahead is modest fixed costs plus an aggressive earning side - our guide covering ways to save outlines the small stuff which adds up over time.

Where does KiwiSaver fit into these rules?

Before any other investing, collect the free money. Contribute at least enough to get your employer's full match and the annual Government contribution of up to $260.72. Then check your fund type matches your timeframe and that your fees are fair - a 0.5% fee difference can cost more than $20,000 over a working life (assuming median wage contributions over 30 years).

I have a mortgage - should I repay it faster or invest?

There's no universal answer, but the maths is a useful anchor - every extra dollar on a 6% mortgage earns a guaranteed, tax-free 6% return, which after-tax investment returns struggle to beat reliably. Many New Zealanders do both: modest extra repayments plus consistent investing (rule 3).

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