Rates & Structure · 23 July 2026
The fix-or-float question is usually treated as a bet on where rates are heading. It is better understood as a question about which risk you can least afford to carry.
A fixed rate locks your interest rate, and therefore your repayment, for an agreed term, commonly six months to five years. A floating rate moves with the market and can change at any time, but lets you repay lump sums without penalty. Fixed buys certainty, floating buys flexibility, and plenty of New Zealand borrowers end up with some of each. The choice is not really a forecast of where rates go next, because nobody reliably knows. It is a decision about which risk hurts you more: an unexpected jump in your repayment, or a break fee when your circumstances change mid-term.
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Both are just ways of pricing the same debt. The difference is what happens between now and the end of the term.
One point that gets lost: an existing fixed rate does not move when the Reserve Bank changes the Official Cash Rate. Floating rates respond quickly and new fixed offers get repriced, but a loan already locked in is untouched until its term ends. Our explainer on how the OCR actually moves your mortgage rate covers that mechanism in detail.
Usually, but not by a fixed margin and not always. Fixed rates are priced off what wholesale markets expect over that term, so when markets expect falls, longer fixed terms can sit below floating; when markets expect rises, they can sit above it. That relationship shifts continually, which is why any article quoting today's numbers is out of date within weeks.
What matters more than the gap on the day is what you do with the flexibility you are paying for. Floating is worth its premium if you genuinely use it to make extra repayments or to stay unencumbered before a sale. If the flexibility sits unused, it is simply a higher rate on that portion of the loan.
The term you pick does two jobs at once. It sets how long your repayment is certain, and it chooses the date you next face the market. The second job gets almost no attention and often matters more.
Short terms give you more chances to react, and equally more chances to be wrong. Long terms give you fewer decision points and a longer commitment if life changes. New Zealand borrowers have leaned short in recent years, and the Reserve Bank noted that close to 40 percent of fixed mortgage lending was estimated to be due for refixing in the first half of 2026, with the share refixed each quarter elevated by historical standards, reflecting that preference for shorter terms (Source: RBNZ, Monetary Policy Statement February 2026).
The practical consequence is a scheduling one. If your whole loan rolls off on a single date, one week's market conditions decides the pricing on all of it. Spreading expiry dates across two or three portions means no single refix carries the whole loan, and you get more than one shot at the market over a cycle.
Fear of being trapped is the single most common reason people give for not fixing, and it is usually based on a misunderstanding of how break fees work.
A break fee compensates your lender for interest it expected to earn over the remaining term. It is worked out from your remaining balance, the time left to run, and how wholesale rates have moved since you fixed. Because it exists to recover a loss, it is asymmetric: if wholesale rates have risen since you fixed, the bank can re-lend that money at a higher rate and there is often little or no loss to recover, so the fee can be small or nil beyond an administration charge. If rates have fallen, the fee can be substantial.
The upshot is that the fear of being locked in is largest in exactly the environment where the lock is loosest. That does not make breaking a good idea, and only your lender can quote the actual figure, usually valid for a few days as wholesale rates move daily. But it is worth asking for the number before assuming a fixed rate rules out selling or restructuring.
Splitting is common in New Zealand and it is often sensible, but "split your loan" on its own is not advice, it is a shape. The useful question is how big each portion should be, and that comes from your own numbers rather than a round percentage.
A reasonable way to think about it: size the floating portion to roughly match the extra repayments you realistically expect to make over the term. If you expect to put a bonus or a work windfall against the loan, that amount has a job to do on floating. If you have never made an extra repayment in five years, a large floating slice is costing you for an option you do not exercise. Our guide to paying off your mortgage faster covers what those extra repayments actually achieve, and the loan repayment calculator lets you test different structures.
Where the wider rate environment comes in is as context, not as an instruction. The Reserve Bank lifted the Official Cash Rate to 2.50 percent on 8 July 2026 and signalled that further increases could follow (Source: RBNZ), which we covered in what the July decision means for your mortgage. A rising-rate environment tends to raise the value people place on repayment certainty, but it does not tell any individual household what to do. That still depends on your income, your buffer, and what you expect to change over the next couple of years. For the mechanics of each loan type, see our mortgage types guide.
A fixed rate locks your interest rate, and therefore your repayment, for an agreed term, commonly between six months and five years. A floating rate moves with the market and can change at any time, usually shortly after the Reserve Bank moves the Official Cash Rate (Source: RBNZ). Fixed gives certainty but limits extra repayments and can cost a break fee if you exit early. Floating lets you repay lump sums without penalty, but your repayment can rise without warning.
Floating is usually priced above the fixed terms on offer, but not always, and the gap changes over time. Fixed rates are priced off what wholesale markets expect over that term, so the relationship between the two shifts as expectations shift. The only reliable comparison is the one your lender or Financial Adviser runs on the day you decide.
The term sets how long your repayment is locked and also chooses the date you next face the market. Short terms mean more chances to react and more chances to be wrong; long terms mean fewer decision points but a longer commitment. The useful questions are how long you need certainty for, and what you expect to change over the next one to three years, such as selling, renovating, income changes, or a lump sum arriving.
Your lender can charge a break fee to compensate for interest it expected to earn over the remaining term, calculated from your remaining balance, the time left, and how wholesale rates have moved since you fixed. Because it recovers a loss, it is asymmetric: when wholesale rates have risen since you fixed there is often little or no loss to recover, and when they have fallen it can be substantial. Only your lender can quote the actual figure, and quotes usually last a few days.
Usually yes, but only up to a limit set by your lender, and the limits differ between banks. Going beyond the allowance can trigger a break cost on the excess. If regular extra repayments are part of your plan, that is worth confirming with your lender or adviser before you fix rather than after.
No. An existing fixed rate does not change during its term, which is the point of fixing. An Official Cash Rate move flows through to floating rates quite quickly and influences the new fixed rates banks offer, but it does not touch a loan already locked in. The Reserve Bank lifted the OCR to 2.50 percent on 8 July 2026 and signalled further increases could follow (Source: RBNZ).
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This article is general in nature and is not financial advice. Interest rates, lender policies, break cost calculations, and lending criteria vary between lenders and change regularly. Always seek advice specific to your situation before making decisions. Trebla Partners Limited, FSP728251. Read our disclosure statement →
