Ten ways to protect your money from inflation

Prices in New Zealand rose about 30 percent in the last six years. Here is how to keep your money ahead of the next six, starting with whatever is most urgent for you.

Here is what $1,000,000 buys in 30 years' time, measured in today's dollars:

• $552,000 at 2 percent inflation
• $412,000 at 3 percent inflation
• $308,000 at 4 percent inflation
• $231,000 at 5 percent inflation

The figures assume a constant rate for 30 years, which shows what compounding does to a fixed sum; actual inflation moves around from year to year. The Reserve Bank targets 2 percent over the medium term, within a 1 to 3 percent range, yet annual inflation has run above the top of that range in most quarters since 2021. Even if we are fortunate enough to return near the target rate, a fixed sum loses close to half its buying power across a working life. Most people meet inflation in smaller ways: the weekly shop, the insurance renewal, the rates bill, and a savings balance which reads the same on the statement while buying a little less each year.

Inflation also moves in long swings. Prices rose about 7 percent in the five years to mid-2020 and about 30 percent in the six years since, with annual inflation at 4.1 percent in the year to June 2026. The surge exposed household finances built on the belief the returns on cash saved in the bank would preserve buying power and household costs would rise gently.

So how do you tell whether your money is keeping up? The useful measure of any savings or investment is the return after all taxes, fees and inflation. A term deposit paying 4 percent leaves between about 2.7 and 3.3 percent after tax, depending on your tax rate, and inflation of 4.1 percent takes both backwards. Subtracting inflation gives a close estimate for a quick comparison; over longer periods compounding also matters.

Where should you start?

Inflation lands differently depending on how your money is arranged, so the first step depends on your circumstances.

• If you carry credit card, personal loan or buy-now-pay-later debt, start there.
• If your mortgage refixes within the next year, start with repayments and cashflow at a higher rate.
• If you hold years of expenses in cash or term deposits, start with the after-tax return on it.
• If you are decades from retirement and your KiwiSaver investment sits in a conservative fund, start with the timeframe.
• If you are retired and drawing income from investments, start with how much short-term certainty you need before the rest of the portfolio faces decades of rising prices.

"For mid-career households, inflation shows up first at the supermarket and then at the mortgage refix. For retirees, it shows up as a widening gap between a fixed income and regular spending. The fix is different in each case, and so is the place to begin."
Nik Velkovski, Private Wealth and Lending Manager, Become Wealth

Protect the next two years

1. Expensive debt first

Credit cards, personal loans, buy-now-pay-later balances and overdrafts charge rates far above anything an investment reliably earns. Clearing debt costing well into double digits is a guaranteed return of the same size, and it frees the cashflow every other step depends on. Rising living costs can push more spending onto credit cards or similar, so this debt grows fastest in the years it hurts most.

2. Cash: how much needs to stay safe?

Keep sums set aside for contingencies and near-term spending safe in a bank account, then ask whether the rest has a purpose or is sitting in cash by habit. Three to six months of living costs is a common starting point for the emergency reserve rather than a rule. A single-earner household, variable income such as being dependent on commissions, or a house old enough to need regular repairs means keeping more. On the contrary, for those with secure income, two earners and low essential spending might mean a smaller contingency sum set aside. Money for planned spending over the next couple of years also stays in cash. Beyond those amounts, holding cash trades a small loss of buying power most years for certainty. Money unlikely to be needed for many years has a better chance in diversified growth assets, provided you can tolerate fluctuating values along the way.

3. Your mortgage at the next refix

Inflation can reduce the burden of mortgage debt over many years. When income rises, a fixed repayment takes a smaller share of it; the catch in New Zealand is fixed terms of one to five years, so borrowers meet current market rates at every refix. The practical step is to work out your repayments at the rate you could refix at today, and again one percentage point higher, then identify what would change in the household budget. Splitting the mortgage across different fixed terms can stop the whole balance refixing on one day. It can also make the loan less flexible and leave part of it on a higher rate for longer, a trade-off a refix or restructure review works through against your own numbers.

4. The numbers inflation quietly moves

Many figures you set years ago can drift out of date as prices rise. The sum insured on a house should track the cost of rebuilding it, so check when the rebuild estimate was last reviewed and whether renovations, demolition and professional fees are included. Household budgets, the emergency reserve target, the cost of a planned renovation and the income assumed for retirement all need the same check. A figure written in today's dollars understates what later years will cost. Automatic contributions set as a fixed dollar amount shrink in real terms every year they stay the same. Setting them as a percentage of income, or lifting them with each pay rise, keeps the saving rate where it was in real terms.

Strengthen the next decade

5. Earning power

Your household inflation rate is personal. A mortgage-free retiree and a renting family with two cars and a daycare bill face different price rises, rather than the published figure. Income growth is personal too. A 4 percent rise on $100,000 adds $4,000 before tax, repeats every year, and every later increase starts from the higher base. Spending cuts eventually reach a limit; income growth can keep compounding, though it takes longer and is not guaranteed. For people with working years ahead, earning power can be one of the strongest defences. The routes include a qualification, a change of role, a negotiation, more hours, and reducing a household's dependence on one income. Self-employed readers face the same test from the other side. Delaying price rises while supplier costs climb means you will fall victim to inflation, so prices, supplier terms and recurring work deserve a yearly review.

6. Shares, held long enough

Shares give you ownership in businesses whose revenue and profits can grow over time. Some businesses pass rising costs on to customers and others lose customers or margin, so the benefit is uneven from one business to the next. Across a diversified portfolio the long record is clear: in every one of the 21 markets with continuous data since 1900, shares have beaten bonds, cash and inflation. They can also fall sharply and visibly before recovering, as they did in 2022 while prices rose fast, so the case rests on holding through the bad years rather than avoiding them. For most people the practical route is a diversified portfolio or fund.

7. KiwiSaver: when will you use the money?

One question is crucial: when are you likely to use this money? A first-home buyer withdrawing in two years and a 35-year-old saving for retirement have little reason to hold the same investment mix. Conservative funds hold mostly bonds and cash, and they tend to lag prices over long stretches. For money needed soon, stability may matter more than beating inflation. For money needed in 30 years, staying too conservative makes the goal harder to reach. Change the fund holding your KiwiSaver investment when your goal, timeframe or tolerance for falls supports it, rather than because inflation has risen or last year's winner looks attractive.

8. Your home, and an investment property, do different jobs

Owning your home takes rent off the list of bills inflation reaches, and a paid-off home takes housing off the list almost entirely. A mortgaged home swaps rent for exposure to interest rates instead. A renter can come out ahead in years when rents stay flat and mortgage rates climb, as they have in parts of New Zealand recently. Rates, insurance and maintenance keep rising for owners either way. An investment property protects you from inflation only if the rent it earns each year and the price it eventually sells for, taken together, leave you better off after every cost. The running costs are interest, council rates, insurance, maintenance, vacancies and tax on rental income; the one-off costs are buying and selling. Values and rents can rise, yet higher inflation also tends to bring higher interest rates, which raise holding costs and can push values down. BNZ reported in June 2026 that house prices sat about 28 percent below their November 2021 peak after inflation. One property can also leave a large part of your wealth dependent on one location and one tenant market. Investment property can preserve wealth over a long period when the purchase price, rent and likely growth justify every cost. The owner also has to hold through falling prices, the inevitable vacancies and maintenance bills, and higher mortgage rates.

Options to consider last

9. Gold

Gold may diversify a portfolio. Its whole return has to come from price gains, as it produces no income. Over the periods most people care about it has been an unreliable match for household prices, on Morningstar's 50-year data. It has helped in some crises, which is a different job from beating inflation.

10. Borrowing to invest

Borrowing to invest is the extreme end of a principle already at work in a mortgage: inflation shrinks fixed debt in today's dollars while the asset bought may rise in price. The price of the debt decides the case. Borrowing at 6 percent to buy an asset expected to return 8 percent leaves little room for tax, fees or disappointment. Compare the return after fees and tax with the full cost of the borrowing; where the margin is narrow, the case rests on an optimistic forecast. Tax treatment varies with what is bought and how the ownership and borrowing are arranged. Gearing accelerates gains and losses alike: the investment falls, the repayments continue, household income tightens, and the investor sells before the market recovers. It belongs last, once everything above is in order.

Inflation's easiest target

Keeping annual inflation at 2 percent is the Reserve Bank's definition of success, though they have failed since 2020. Even if they succeed and inflation reverts to just 2 percent annually, the real value of each dollar still halves across a working life. Inflation's easiest target is a balance left in a savings account or similar untouched for years. Choose the one step above which fits your situation, and take it before the next round of price rises.