When to Fix Your Mortgage NZ — Timing Your Rate Decision

The question every NZ mortgage holder faces at rollover: fix now, or wait? And if fixing, which term? These decisions can save or cost thousands of dollars — but they involve genuine uncertainty about where interest rates are heading.

This guide gives you a clear framework for thinking through the decision.

The Fundamental Challenge: No One Knows for Certain

Rate decisions are ultimately forecasts. The RBNZ, the major banks, and financial markets all publish rate forecasts — but history shows they’re often wrong. During 2020–2022, “experts” consistently predicted rates would stay low; by 2023, the OCR had hit 5.50%, the highest in over 15 years.

The goal is not to perfectly predict rates, but to make a decision that aligns with your risk tolerance, financial situation, and the balance of probabilities based on available information.

Step 1: Understand the Current Rate Environment

Before deciding when or how long to fix, understand where rates are and where they might be heading.

Key indicators to check:

Indicator	Where to find it	What it tells you
Current OCR	RBNZ website	Current short-term borrowing cost for banks
RBNZ OCR forward guidance	Monetary Policy Statement (8× per year)	RBNZ’s own rate forecast
Wholesale swap rates	Financial markets / bank treasury pages	Market’s expectation of future rates (priced into fixed mortgage rates)
Current bank carded rates	Each bank’s website	Actual fixed rates available today
Economist forecasts	Interest.co.nz, NZ Herald, major bank economists	Independent rate predictions

As at April 2026: The RBNZ has been in an easing cycle since late 2024, having cut the OCR from the 5.50% peak. Market expectations (as priced into swap rates) suggest the OCR may fall further through 2026 before stabilising. This environment — declining rates — generally favours shorter fixed terms (1 year or less), so you can roll over to lower rates sooner rather than being locked in.

Step 2: Choose a Term Based on Your View

If you believe rates will fall

Strategy: Fix for a shorter term (6 months or 1 year) so you can refix at lower rates when your term expires.

1-year fixed at 5.55% today
If rates fall to 4.80% in a year, you roll over at 4.80%
Total benefit: 0.75% rate reduction from the next term

Risk: If rates rise instead of fall, you’re in a worse position at rollover.

If you believe rates will rise

Strategy: Fix for a longer term (2–5 years) to lock in today’s rates before they increase.

5-year fixed at 5.89% today
If rates rise to 7.00% over the next 2 years, you’re protected at 5.89% for 5 years
Total benefit: significant, if rates rise significantly

Risk: If rates fall, you’re locked into a higher rate and face large break fees if you want to exit.

If you’re uncertain (the most common situation)

Strategy: Split your mortgage across multiple terms to diversify risk.

50% fixed 1 year (5.55%)
50% fixed 2 years (5.45%)

Part of your mortgage benefits if rates fall (the 1-year portion rolls over sooner). Part is protected if rates stay flat or rise (the 2-year portion locks in today’s rate).

This is not trying to beat the market — it’s managing uncertainty prudently.

Step 3: Compare the Rate Curve

The term structure of rates (yield curve) tells you how much extra you pay for longer certainty. In April 2026:

Fixed term	Indicative rate
6 months	~6.19%
1 year	~5.55%
2 years	~5.45%
3 years	~5.55%
4 years	~5.79%
5 years	~5.89%

The cheapest current option is the 2-year fixed rate (~5.45%). The 1-year is slightly more expensive (5.55%) but gives you the ability to refix in 12 months if rates fall. The 5-year gives certainty but at a premium.

The inverted curve observation: When short-term rates are higher than long-term rates (as in the 6-month rate being above the 2-year rate here), it typically means the market expects rates to fall. This is consistent with an OCR easing cycle — banks can offer lower 2-year rates because they expect funding costs to fall over the period.

The “Wrong” Decision Risk

What if I fix long and rates fall? If you fix 5 years at 5.89% and rates fall to 4.50% in 2 years, you have three options:

Continue paying 5.89% for the remaining 3 years (cost: ~$41,000 extra on $600,000 vs 4.50%)
Pay a break fee to exit early and refix at 4.50% (break fee could be $20,000–$40,000)
Sell the property (which also triggers the break fee)

What if I fix short and rates rise? If you fix 1 year at 5.55% and rates rise to 7.00% in 12 months, you refix at 7.00%. The cost is the rate increase applied to your balance for future terms — no break fee, just higher ongoing repayments.

The asymmetry: fixing long and being wrong creates break fee risk. Fixing short and being wrong creates repayment risk. For most borrowers, repayment risk is more manageable than large one-time break fees.

What NZ Borrowers Actually Do (2026)

The majority of NZ borrowers currently (April 2026) are fixing for 1–2 years, reflecting:

Market expectation that rates will fall through 2026
Desire to benefit from lower rates at next rollover
The 1-2 year rate being cheapest on the curve

The 1-year fixed rate has historically been the most popular choice in NZ. Since the easing cycle began, shorter terms have been favoured by most borrowers and advisers.

Practical Decision Framework

Fix for 1 year if:

You believe the OCR will fall further through 2026
You want flexibility to access lower rates at rollover
You don’t need long-term payment certainty
Your budget can handle moderate repayment variation

Fix for 2 years if:

You want a balance of rate certainty and flexibility
The 2-year rate is meaningfully lower than the 1-year rate
You’re unlikely to make major financial changes in the next 2 years

Fix for 3–5 years if:

You have high income uncertainty and need budgetary certainty
You believe rates will rise significantly and want to lock in today’s rates
You’re taking out a large loan and any rate rise would cause genuine financial stress