Mortgage decisions / NZ

Refix with your bank or refinance?

When your fixed rate is ending, the cheapest looking rate is not always the better deal. Compare what you will actually pay and receive if you stay, negotiate or move.

By Nathan Dyson, MyChange mortgage adviser Updated September 2026

The short answer

Stay if the total offer is stronger. Switch if the numbers and structure make sense.

Refixing means selecting a new fixed term with your existing lender. Refinancing means moving the lending to another lender, usually with a new application and legal work. Before accepting either offer, ask your bank about a competitive rate and any retention contribution, then compare that with the complete offer from another lender.

The comparison

Put both offers on the same page.

Choose the same comparison period for each option. Record these numbers rather than comparing advertised rates or cashback in isolation:

Interest and repayments

Compare the rates actually offered to you, the fixed terms, repayment amounts and expected interest over that period. Check whether the loan term or balance would change.

Cash you can keep

Include a new lender's cash contribution and any retention contribution offered by your current bank. Check the conditions and repayment dates for both.

Costs of moving

Ask about legal, discharge, valuation and application costs; a possible fixed-rate break fee; and repayment of an earlier cash contribution if you leave during its clawback period.

Fit and approval

Consider offset or revolving credit, extra repayments, loan splits and service. A new lender also has to assess your application; a lower advertised rate is not an approval.

Worked example

What a cashback headline can hide.

Imagine $700,000 of lending. A new lender offers a rate 0.20 percentage points lower for one year and a $7,000 cash contribution. Your existing bank offers $1,500 to stay. Moving costs $1,800 in legal fees, and leaving now requires repaying $4,500 of an earlier cash contribution.

Approximate one-year interest difference*+$1,400

New lender cash contribution+$7,000

Legal costs and old cashback repayment−$6,300

Current bank's retention offer you give up−$1,500

Illustrative advantage from moving$600

*For a simple illustration, 0.20% × $700,000 = $1,400. Actual interest savings depend on balances, repayment timing and the loan terms. This example omits other possible fees and future outcomes; it is not a quoted offer.

A $7,000 cashback sounds decisive. Once the other terms are counted, this example is close enough that flexibility, effort, timing and approval risk matter too. Waiting until the old cashback repayment period ends could change the result again.

How to decide

When each option tends to fit.

Refix or negotiate with your bank

Consider staying when its rate and contribution are competitive after costs, your structure still fits, or moving would trigger a substantial break cost or cashback repayment.

Apply to refinance

Consider moving when another lender offers a better overall outcome after costs, or your current bank cannot offer the structure or lending you need. Check eligibility before relying on the proposed offer.

Check the numbers yourself

Independent tools and reading

These are useful alongside a written offer from each lender. Advertised rates and online estimates cannot confirm the terms available to you.

interest.co.nz home-loan comparison calculator MoneyHub's guide to mortgage cash contributions interest.co.nz break-fee estimator

Before you sign

Five questions to ask.

What rate and cash contribution will my existing bank offer to keep my lending?
What would I repay from my previous cashback if I moved on the proposed date?
Would I pay a fixed-rate break fee, and can the bank give me a current estimate?
What legal, valuation or other costs would the new lender cover?
How do the repayment, loan structure and future flexibility compare?

Your next move

Have an offer from your bank?

Send Nathan your fixed-rate expiry date, current lender, approximate loan balance and the offer you have received. He can review whether negotiating, refixing or assessing a refinance is the useful next step.

Ask Nathan for a review Or send a website enquiry

Please do not email bank statements, identity documents or other sensitive files at this stage.