Mortgage Break Fees in NZ: How They Work and What You'll Pay

What a break fee is and why banks charge it

When you fix your mortgage, your bank doesn't simply hold the money in a vault waiting for your monthly payment. It funds your loan through the wholesale money market, borrowing at a fixed rate for the same term as your fixed mortgage. When you break your fixed rate early — by selling, refinancing or restructuring — the bank has to unwind that wholesale funding position.

If current wholesale rates have fallen since the bank arranged your funding, it now has to reinvest the money at a lower rate than it's paying. That loss is passed on to you as a break fee. If rates have risen, the bank can reinvest at a higher rate — meaning it's actually in a better position — so you typically owe nothing (or pay only a small administration fee).

This is why break fees are entirely tied to rate movements, not a flat penalty for leaving early.

How the calculation works

The exact formula varies slightly between banks, but the general approach is:

Break Fee = Outstanding Loan Balance × (Fixed Rate − Current Wholesale Rate for Remaining Term) × Remaining Term in Years

The "current wholesale rate" is the bank's wholesale swap rate for whatever time is left on your fixed term. This is not the same as the advertised fixed mortgage rates customers see — it's an internal funding rate the bank uses.

For example: you have $450,000 remaining on a 2-year fixed rate you took out at 6.5%. You're 9 months in, so 15 months remain. The current 15-month wholesale swap rate is 5.2%. The rate difference is 1.3%. Very roughly: $450,000 × 0.013 × (15/12) = around $7,313. This is an approximation — banks use more precise daily calculations — but it gives you a working estimate of the magnitude.

When your break fee is zero (or close to it)

The break fee is zero when current wholesale rates are at or above the rate your bank locked in to fund your mortgage. This tends to happen when:

• Interest rates have risen since you fixed — which means if you fixed at 5% and rates are now 7%, the bank can re-lend your money at a higher rate than it's costing them, so you owe nothing on the rate differential
• You're very close to the end of your fixed term, where the remaining time is so short that even a meaningful rate gap produces a minimal dollar amount
• Your remaining balance is small

In a rising rate environment, many people find they can break and refinance with little or no fee. In a falling rate environment (which is precisely when people most want to break to access lower rates), break fees can be substantial.

Common situations where people break their mortgage

• Selling the property. When you sell, the mortgage is repaid. If you're in a fixed term, a break fee applies. Some people factor this into their sale timeline — selling at or close to a refix date to minimise or eliminate the fee.
• Refinancing to a better rate. If rates have dropped significantly, refinancing can still make sense even with a break fee, if the savings over the remaining term outweigh the cost. You need to do the maths carefully.
• Property purchase falling over. If you pre-arranged a mortgage for a property that didn't settle, you may face a break cost to exit the funding the bank arranged.
• Restructuring your mortgage. Moving from a split structure to a different one, or consolidating loans, may require breaking a fixed portion.
• Significant lump sum repayments. Paying down your mortgage beyond your bank's allowed annual threshold can trigger a partial break fee on the excess amount.

How to get the actual number from your bank

Because the calculation depends on current wholesale rates that change daily, the only way to get an exact break fee is to ask your bank directly. Most banks will provide a break fee quote over the phone or through internet banking within 24 hours. The quote is typically valid for a short window (24–48 hours) because wholesale rates move.

Ask for the break fee quote before making any firm decisions. If you're selling and the settlement date is flexible, knowing the fee might influence your timeline. If you're refinancing, you need the exact number to compare it against the savings from the lower rate you're moving to.

Is it worth breaking to get a lower rate?

The break-even analysis is straightforward: take your break fee, divide it by the monthly saving you'll get from the lower rate, and that tells you how many months it takes to recover the cost.

Break Fee ÷ Monthly Saving = Break-Even Period in Months

If the break-even period is shorter than the time remaining on your planned ownership of the property, breaking makes financial sense. If you're planning to sell in 18 months and the break-even is 24 months, it doesn't make sense regardless of how good the new rate looks.

There's also a secondary consideration: if rates continue to fall after you break, you'll benefit from that too. And if they rise, the certainty of a new fixed term protects you. The break decision isn't just about the rate differential today — it's also about where you think rates are going after the break.

One final point: bank pricing doesn't always reflect the fee

Some banks offer cash contributions when you refinance to them. These can range from a few hundred dollars to several thousand, depending on your loan size. A cash contribution from a new lender can offset some or all of a break fee from your existing lender. If you're thinking about breaking to refinance, get quotes from competing banks first — the net cost of moving might be much lower than the headline break fee suggests.

Break fee estimates are for guidance only and should not be relied upon for financial decisions. Your bank is the only source of an accurate, legally binding break fee quote. Always get a written quote from your lender before proceeding.