How the OCR Actually Affects Your Mortgage
Every six to eight weeks the Reserve Bank of New Zealand (RBNZ) reviews the Official Cash Rate, or OCR. When it moves, the headlines react instantly. But the link from "OCR cut by 25 basis points" to "my mortgage repayment changes by X dollars" is not always direct. Understanding that link is the difference between making reactive financial decisions and confident ones.
What the OCR actually is
The OCR is the interest rate the Reserve Bank pays the trading banks for their settlement-account balances. By raising or lowering this rate, RBNZ influences the cost at which banks lend to each other, which in turn influences the rates banks offer customers. It is a blunt tool for managing inflation and the broader economy.
Floating rates respond first
Bank floating mortgage rates track the OCR closely. When the OCR moves, you can usually expect a corresponding floating-rate change from the major banks within a week or two. If you are on a floating loan, your monthly repayment will change directly — although you can usually elect to keep payments the same and shorten the term instead.
Fixed rates work differently
Fixed mortgage rates are not set off the OCR — they are set off "swap" rates in the wholesale market. Swap rates reflect the market's expectation of where the OCR will be over the term of the fix. That is why fixed rates often move before the OCR — sometimes weeks before — once traders price in the next move.
For homeowners this has a counter-intuitive consequence: if the RBNZ surprises the market with an OCR cut, fixed rates may barely move because the cut was already priced in. If RBNZ holds when a cut was expected, fixed rates can actually rise.
What an OCR change means in dollars
A 25-basis-point change (0.25 percent) on a 500,000 dollar mortgage over 25 years moves the monthly repayment by roughly 70 dollars. Across a 30-year term that compounds — small changes really do matter, but not by enough to justify panic.
If the OCR cycle is going up and you are on a short fix that rolls off in three months, you face a re-pricing risk. If it is going down, locking in a long fixed term too early can mean missing out on cheaper rates.
What you can actually do
You cannot control the OCR. What you can control is your loan structure:
- Keep some of your loan floating so you can capture downward moves
- Stagger fixed terms so you do not re-price the entire mortgage in one shot
- Make extra repayments while rates are higher — your principal shrinks faster
- Consider an offset or revolving credit account if you regularly hold cash
The right structure depends on your income stability, cash buffer, and risk tolerance. Have a conversation with us before your next re-fix — we will model the scenarios so you can choose with eyes open.