Refinancing Your Mortgage in NZ: When Does It Make Sense?

Refinancing — moving your mortgage from one lender to another, or restructuring it inside your existing lender — can save significant money, but only when the maths actually works. Done at the right moment it can put tens of thousands back in your pocket over the life of the loan; done at the wrong moment it costs more in fees than it ever saves. Here is the framework we use with clients to decide whether to move, and when.

What refinancing actually involves

There are two distinct things people mean by "refinancing":

Switching lenders — discharging your mortgage from one bank and registering a new one with another, usually to chase a better rate or a cash contribution.
Restructuring — keeping the same lender but changing how the loan is set up: splitting it across terms, adding an offset, changing repayment frequency, or topping it up.

Both are worth considering, and they are not mutually exclusive. The right answer depends entirely on your numbers, so the first step is always to run them.

The break-even calculation

The single most important number is your break-even point — how long it takes for the savings to outweigh the costs of moving.

Refinancing carries costs: legal fees of roughly 1,000 to 1,500 dollars to discharge and re-register the mortgage, sometimes a valuation fee, and potentially break fees if you are still inside a fixed term.

The savings come from a lower interest rate, a cash contribution from the new bank, or both. A worked example makes it clear:

On a 500,000 dollar loan, saving 0.5 percent is 2,500 dollars a year. Against roughly 1,500 dollars of costs, you break even in well under a year — a clear win.
Saving just 0.1 percent on the same loan is 500 dollars a year. After costs it takes around three years to break even, by which time you may have re-fixed and the saving evaporated.

The rule of thumb: the bigger the loan and the bigger the rate gap, the faster refinancing pays for itself.

When refinancing usually pays off

Refinancing tends to be a clear win when:

Your fixed term has rolled off, so there are no break costs to worry about.
A new lender is offering a meaningful cash contribution (3,000 to 5,000 dollars is common in competitive markets).
The rate gap between your current deal and the new one is at least 0.3 percent.
You have more than five years remaining on the loan, so the savings have time to compound.
You are comfortable committing to the new bank for its clawback period (usually three to four years).

When refinancing usually does not pay off

It rarely makes sense when:

You are deep inside a fixed term — break fees can dwarf any rate saving.
The rate gap is small (under 0.2 percent).
You have only a year or two left on the loan.
Your equity has dropped or your income has changed, so you may not qualify with the new lender on the terms you expect.

The cash contribution game

Most New Zealand banks offer cash contributions to new mortgage customers — typically 0.6 to 1 percent of the loan amount, capped at a few thousand dollars. A 600,000 dollar loan can attract 3,000 to 6,000 dollars in cash, and in hot markets banks sometimes sweeten this further to win business. This is real money and is often the single factor that tips a refinance from "marginal" to "worth it".

The catch is the clawback. Almost every cash contribution comes with a condition: if you refinance again or repay the loan inside the clawback period (usually three or four years), you have to repay the cash — sometimes in full, sometimes pro-rata. So a cash contribution only truly counts as a saving if you intend to stay put for the full period. Factor that commitment in before you let the cash decide.

Break fees: how they actually work

If you are inside a fixed term, leaving early can trigger a break fee (sometimes called an early repayment recovery). It is not a flat penalty — it is the bank recovering the difference between the rate you locked and the lower rate at which it can now re-lend that money.

That means break fees are large when wholesale rates have fallen sharply since you fixed, and close to zero when rates have risen. There is no way to know your exact break fee without asking the bank for a written quote, valid on the day. Never assume it is too high to bother checking, and never assume it is trivial — get the actual figure and feed it into the break-even maths.

Restructuring without switching banks

Sometimes the cleanest move is not to switch banks at all, but to restructure inside your existing one:

Split the loan across multiple fixed terms so you are not re-pricing everything on one date.
Add an offset or revolving credit facility if you regularly hold cash, so that balance reduces the interest you pay.
Switch to fortnightly payments, which sneaks in the equivalent of an extra monthly payment each year and shortens your term.
Top up for renovations or debt consolidation against your existing equity.

None of these involve legal fees or clawbacks — just a tidier structure that fits your goals. If your current bank's rates are competitive, restructuring can capture most of the benefit of refinancing without the cost or hassle.

The refinance process, step by step

If switching does stack up, here is broadly how it runs:

We compare current offers across lenders, including rates and cash contributions, against your existing deal.
You get pre-approval with the chosen new lender, subject to valuation and documentation.
A solicitor handles the discharge from your old bank and the new registration.
The new loan draws down, your old loan is repaid, and any cash contribution is paid to you.
The whole process typically takes two to four weeks once your paperwork is in.

Documents you will usually need

Recent payslips or, if self-employed, financial statements and tax returns.
Bank statements showing your income and regular expenses.
A record of your current mortgage balance and fixed-term expiry.
Identification and proof of your current address.

Having these ready up front is the easiest way to keep a refinance moving quickly.

Frequently asked questions

Will refinancing hurt my credit? A new application involves a credit check, which can cause a small, temporary dip. It is rarely a deciding factor, and a well-prepared application keeps enquiries to a minimum.

Can I refinance to consolidate other debt? Often yes — folding higher-interest debt into your mortgage can cut your overall interest cost, provided you do not simply free up the old limits and run them up again. We will model whether it genuinely helps.

How often can I refinance? As often as the maths supports, but the clawback periods on cash contributions usually make refinancing more than once every three to four years uneconomic.

Is restructuring with my current bank really cheaper? Usually, because it avoids legal fees and clawbacks. Whether it captures enough of the benefit depends on how competitive your current bank's rates are.

Refinancing an investment property

The principles are the same for investors, but a few factors carry extra weight. Investor LVR limits are tighter, so if your property's value has slipped, you may not have the equity to move lenders on the terms you want. Cash contributions are often available on investment lending too, but the clawback discipline matters even more because investors tend to restructure more frequently. And because interest deductibility and tax treatment interact with how the loan is structured, it is worth coordinating any refinance with your accountant so the new structure supports your tax position rather than working against it.

Should you refinance to renovate?

A common reason to refinance or restructure is to fund renovations by topping up against your equity. This can be smart — borrowing at mortgage rates is far cheaper than a personal loan or credit card, and a well-chosen renovation can lift the property's value by more than it costs. The discipline is to ring-fence the top-up for the project, keep it on a sensible term rather than dragging a short-term cost across 30 years, and confirm the numbers stack up before you commit. We will help you size the top-up and structure it so the repayments stay manageable.

The bottom line

Refinancing decisions are made one bank at a time, and the right answer depends on your specific loan balance, remaining fixed term, equity position, and the cash deals on offer that week. Talk to SMS Loans before you sign any mortgage transfer paperwork — we will tell you whether the deal you have been quoted is actually the best option, or whether a quiet restructure with your existing bank gets you most of the way there for a fraction of the cost.