Fixed rates on an investment loan lock in your interest cost for a set period, protecting rental yield calculations from rate rises. The trade-off is a break cost if you exit, refinance or repay beyond your allowed limit before the fixed term ends.
How a Fixed Rate Lock Protects Investor Cashflow
A fixed rate holds your interest cost constant for one to five years, which means your monthly repayment and net rental position remain predictable. Consider an investor who purchases a two-bedroom apartment in South Yarra and fixes the rate at the time of settlement. If variable rates climb by one percentage point over the following 18 months, the investor's cashflow remains unchanged while comparable properties on variable rates see repayments rise and net rental losses widen. That stability matters when you're managing multiple properties or calculating whether the investment remains cash neutral. The fixed period gives you certainty over exactly how much the loan will cost, making budgeting and tax planning more reliable.
The certainty ends when the fixed term expires. At that point, your loan reverts to the lender's standard variable rate unless you negotiate a new fixed or discounted variable arrangement. Investors who fixed during a low-rate environment and revert during a higher-rate cycle can see repayments jump significantly, so it's worth contacting your broker or lender at least 90 days before the fixed term ends to discuss your refinancing options.
What Triggers a Break Cost on an Investment Loan
A break cost arises when you discharge, refinance, switch to variable, or make a repayment above your annual prepayment allowance during a fixed rate period. Most lenders allow between zero and 10 per cent of the original loan amount to be repaid each year without penalty. Selling the property, accessing equity to purchase another asset, or refinancing to a different lender all require full discharge and will trigger a break cost if the wholesale cost of funds has moved against the lender since you fixed.
In our experience, investors in South Yarra often trigger break costs unintentionally when they sell one property to fund a deposit on another, or when they consolidate multiple loans to access a better rate. The cost can run into tens of thousands of dollars if fixed rates have fallen significantly since you locked in, because the lender is compensating for the difference between what you're paying and what they can now lend that money for in the wholesale market.
How Lenders Calculate the Break Cost Figure
The break cost is the economic loss the lender incurs by allowing you to exit the fixed contract early. Lenders calculate it by comparing the fixed rate you're paying with the current wholesale rate for the remaining term of your fixed period, then applying that difference to your outstanding balance.
As an example, an investor with a $600,000 investment loan fixed at 5.5 per cent with three years remaining decides to sell the South Yarra apartment and discharge the loan. The lender's current three-year wholesale rate has dropped to 4.8 per cent. The lender calculates the present value of the interest shortfall over the remaining 36 months, which in this scenario could amount to a break cost in the range of $12,000 to $15,000, depending on the lender's exact methodology and any administration fees. If rates had risen instead, the break cost would typically be zero because the lender can reinvest the funds at a higher return.
Each lender uses a slightly different formula, and some apply a margin or administration fee on top of the raw economic cost. The calculation is always based on wholesale funding rates, not the advertised retail fixed rates you see on comparison sites. Most lenders will provide a break cost estimate on request, and that figure is usually valid for five to seven business days.
Why Split Loan Structures Reduce Break Cost Exposure
Many investors split their loan between fixed and variable portions to maintain flexibility while still locking in part of their rate. A common structure is 50 per cent fixed and 50 per cent variable, though the split can be adjusted to suit your risk tolerance and refinancing plans. The variable portion allows you to make unlimited extra repayments, access offset or redraw, and refinance without penalty. The fixed portion provides rate protection on half the loan.
If you need to exit or refinance during the fixed period, the break cost applies only to the fixed portion of the loan. An investor with a $700,000 investment loan split evenly between fixed and variable would face a break cost calculation on $350,000 rather than the full amount, which can halve the exit penalty. Split structures also allow you to stagger your fixed rate expiry dates by fixing each portion for different terms, which smooths out your exposure to rate movements when the fixed periods end.
Fixed Rate Lock-Ins Under the New Negative Gearing Rules
From 1 July 2027, net rental losses on residential investment properties acquired on or after 12 May 2026 can only be offset against other residential rental income or carried forward, unless the property qualifies as an eligible new build. The quarantine doesn't change how fixed rates or break costs operate, but it does change the cashflow appeal of fixing.
Investors who can no longer offset rental losses against wage income may prioritise interest-only repayments and variable rates to preserve flexibility, rather than locking in a fixed rate for multiple years. On the other hand, investors purchasing eligible new builds in South Yarra, such as new apartments in developments along Toorak Road or St Kilda Road, retain full negative gearing and may value the certainty of a fixed rate more highly because their tax position remains unchanged. The choice depends on whether your property falls under the new rules and how you weight cashflow certainty against refinancing flexibility over the next few years.
When Refinancing Before the Fixed Term Ends Makes Sense
Refinancing during a fixed period is worth considering if the interest saving or equity access outweighs the break cost. Calculate the monthly saving from the new rate, multiply by the number of months remaining on your fixed term, and compare that total to the break cost estimate. If the saving exceeds the cost within 12 to 18 months, refinancing is usually viable.
Investors in South Yarra with properties that have appreciated significantly since purchase may also refinance to release equity for a second purchase, even if a break cost applies. Accessing $100,000 in equity to fund a deposit on another property can justify a $10,000 break cost if the alternative is waiting two or three years for the fixed term to expire while the market moves. Your broker can request break cost estimates from your current lender and model the scenarios before you commit.
What to confirm with your broker before you lock in a fixed rate on an investment loan. Confirm your prepayment allowance, whether partial or full offset is available during the fixed term, and whether the lender permits switching part of the fixed balance back to variable without a full discharge. Some lenders allow limited flexibility within a fixed contract, while others enforce strict terms. Also confirm how the lender calculates break costs and whether they cap the administration component, because a five-figure break cost can erase years of rate protection if you need to exit early. If you're planning to sell or refinance within three years, a shorter fixed term or a split structure is usually more appropriate than locking in for five years.
Call one of our team or book an appointment at a time that works for you to discuss your fixed rate options and how to structure your investment loan to suit your portfolio plans.
Frequently Asked Questions
What is a break cost on a fixed rate investment loan?
A break cost is the economic loss a lender incurs when you exit, refinance or repay above your limit during a fixed rate period. It's calculated by comparing your fixed rate with the lender's current wholesale rate for the remaining term, applied to your outstanding balance.
Can I avoid a break cost if I sell my investment property during a fixed term?
No, selling the property and discharging the loan during a fixed term will trigger a break cost if wholesale rates have fallen since you locked in. The only way to avoid it is to wait until the fixed period expires or have rates rise above your fixed rate.
Does splitting my investment loan between fixed and variable reduce the break cost?
Yes, a split loan structure means the break cost applies only to the fixed portion of the loan. If you have a 50/50 split, you would face a break cost on half the balance, which can significantly reduce the penalty if you need to refinance or sell early.
How do the new negative gearing rules affect fixed rate decisions for investors?
From 1 July 2027, rental losses on most properties acquired after 12 May 2026 cannot be offset against wage income, which may make variable rates and flexibility more appealing. Investors buying eligible new builds in South Yarra retain full negative gearing and may still value the certainty of a fixed rate.
When does refinancing during a fixed term make financial sense?
Refinancing is worthwhile if the interest saving over the remaining fixed term exceeds the break cost, typically within 12 to 18 months. It can also make sense if you need to access equity for another purchase and the break cost is outweighed by the opportunity.
