Understanding break costs on fixed-rate home loans.
Fixed-rate home loans offer stability, certainty, and predictable repayments — but they also come with a lesser-known feature that often catches borrowers off guard: break costs.
Break costs aren’t penalties. They’re a financial adjustment lenders apply when you end a fixed-rate loan early, and they are closely linked to wholesale market interest rates. Understanding how they work helps you plan ahead and make confident decisions about fixing, refinancing or selling a property.
At Lumo, we explain these calculations clearly so you know what to expect before making changes to your loan.
What are break costs?
Break costs (sometimes called economic costs) are fees a lender may charge if you:
Sell a property during a fixed-rate term
Refinance to another lender before the fixed term ends
Switch from fixed to variable early
Make extra repayments above the allowable limit
Fully pay out a fixed-rate loan before expiry
You’re essentially ending the fixed-rate contract early. If that change leaves the lender worse off financially, they pass on the economic difference as a break cost.
How lenders calculate break costs (the simple explanation)
Break costs are based on movements in wholesale interest rates — usually the Bank Bill Swap Rate (BBSW) or an equivalent benchmark.
A lender compares:
The wholesale rate on the day you originally fixed your loan
versusThe wholesale rate applicable to the remaining fixed period at the time you break
The key principle is:
If wholesale rates have risen since you fixed → the lender can re-lend the funds at a higher rate → break cost is small or zero
If wholesale rates have fallen → the lender would make less re-lending the money today → break cost applies
The lender is not “charging a fee” — they are recovering their economic loss.
A simple example
Let’s say you:
Fixed a $650,000 loan for 2 years
Sell the property after 1 year
Meaning 1 year remains on the fixed term
Wholesale rates have fallen by 0.25% (0.0025) since the day you fixed
A simplified break cost calculation:
0.0025 × $650,000 × 1 year = $1,625
This is not the exact formula lenders use — the real calculation has more variables — but it demonstrates the core idea.
If rates had risen instead of fallen, that cost might have been zero.
Why break costs vary so much
Break costs depend on:
How much time remains on the fixed term
The size of your loan
Whether you’ve prepaid more than the allowed limit
How much wholesale rates have moved
The lender’s own wholesale pricing methodology
This is why some borrowers break a fixed rate and pay nothing, and others face a substantial cost.
Every lender uses its own proprietary calculation, but all follow the same economic principle.
Extra repayments and break costs
Most lenders allow up to a certain amount of extra repayments during a fixed term.
If you exceed this allowance, break costs may apply.
For example:
A lender may allow $10,000–$30,000 in extra repayments per fixed period
If you exceed that amount, the lender may view it as “partial breakage” of the fixed contract
Break costs apply to the excess amount
This is why borrowers sometimes split their loans — keeping part fixed for stability and part variable for full flexibility.
Other limitations on fixed loans
Break costs aren’t the only consideration. Most lenders also apply:
No offset account against fixed portions (with few exceptions)
Extra repayment limits
Reduced redraw availability
Less flexibility for restructures
No ability to switch loan purpose mid-term without reassessment
Fixed loans are great for certainty, but not ideal if your plans may change.
When break costs matter most
Break costs are a key consideration when:
You’re planning to sell within the fixed term
You expect to refinance soon
You want to make large extra repayments
Rates are falling or volatile
You’re considering interest-only periods with fixed segments
You’re restructuring ownership (e.g., moving home to investment)
Before fixing, we always talk through your likely plans over the fixed period to avoid unexpected costs later.
When break costs don’t matter as much
Break costs tend to be minimal or zero when:
Rates are rising
You intend to hold the property long-term
You’re not planning any large extra repayments
The loan amount is small
The fixed period is short
In recent years, some borrowers have broken fixed loans and paid nothing — purely because wholesale rates had risen.
Can you estimate break costs in advance?
Yes — lenders can provide an estimate, but:
It changes daily with wholesale rates
It isn’t guaranteed
The only exact figure is calculated on the day you break the loan
At Lumo, we request (or help you to order) updated estimates for clients anytime they’re considering switching, refinancing or selling.
Let’s chat.
If you're thinking about breaking a fixed rate — or deciding whether to fix in the first place — we can run the numbers, explain the risks, and help structure your loan to avoid unnecessary costs. Let’s chat.
This page provides general information only and has been prepared without taking into account your objectives, financial situation or needs. We recommend that you consider whether it is appropriate for your circumstances and your full financial situation will need to be reviewed prior to acceptance of any offer or product. It does not constitute legal, tax or financial advice and you should always seek professional advice in relation to your individual circumstances. Subject to lenders terms and conditions, fees and charges and eligibility criteria apply.