Fixed investment loan interest rates provide certainty, but most products prohibit or limit extra repayments without incurring penalties.
For contractors with irregular income streams, the inability to draw down surplus cash after making additional repayments can create genuine cashflow risk during gaps between projects. You need a structure that protects both certainty and liquidity.
Fixed Rate Loan Structures That Preserve Cashflow Access
Most lenders cap extra repayments on fixed rate investment loans at between $10,000 and $30,000 per year without penalty. Once paid, those funds are locked inside the loan until the fixed term expires or you refinance and pay break costs.
Consider a contractor who fixes 60 per cent of a loan amount at 5.89 per cent and leaves 40 per cent variable at 6.34 per cent. The fixed portion provides rate protection across the majority of the debt. The variable portion carries an offset account. Surplus income from completed projects sits in offset, reducing interest on the variable portion while remaining fully accessible if work slows or an equipment purchase becomes necessary. At current variable rates, every $50,000 in offset saves roughly $3,170 per year in interest on the variable split without reducing the deductible loan balance.
The alternative approach is fixing the entire loan amount and parking surplus cash in a separate savings account. That cash earns taxable interest at rates well below the interest rate you continue to pay on the full loan balance, and you lose the arbitrage.
Why Break Costs Exist and How They Are Calculated
A break cost is the economic loss a lender incurs when you exit a fixed rate loan early. Lenders fund fixed loans by borrowing at a wholesale rate locked for the same term. When you break early, the lender still owes that funding cost but no longer receives your repayments to cover it.
The calculation compares the fixed interest rate on your loan to the current wholesale rate for the remaining fixed term. If wholesale rates have fallen since you fixed, the lender cannot reinvest the returned principal at the same return, and you pay the difference. If rates have risen, there is typically no break cost.
Break costs are not penalties. They are reimbursement of the lender's funding loss. They can run into tens of thousands of dollars if rates drop sharply after you fix. This makes access to liquid funds through an offset on a variable split more valuable than the ability to make penalty-bearing extra repayments on a fully fixed loan.
Interest-Only Terms With a Fixed Rate Component
Investor loans allow interest-only periods, typically up to five years initially. Principal and interest repayments reduce debt but also reduce the deductible loan balance, which erodes one of the core tax benefits of holding investment property.
You can fix an interest-only loan. The fixed rate applies to the interest component only. Because you are not reducing principal, the monthly repayment remains constant and lower than a principal and interest equivalent, which improves serviceability for contractors whose income can fluctuate.
Once the interest-only period expires, the loan reverts to principal and interest and the repayment rises. If that reversion coincides with the end of the fixed term, you have the option to refinance or restructure. If the fixed term extends beyond the interest-only period, the repayment increase occurs mid-fix and you are committed to the higher repayment amount until the fixed term ends or you pay break costs.
When structuring a split loan, you can apply different interest-only periods to each split. For example, a five-year interest-only term on the fixed portion and a principal and interest structure on the variable portion. This allows voluntary principal reduction on the variable split without affecting the longer-term rate protection or the deductible balance on the fixed split.
Portfolio Growth and the Impact of DTI Caps on Contractors
From 1 February 2026, ADIs apply a debt-to-income cap under APRA prudential settings. Lenders may only approve 20 per cent of new investor loans at a DTI of six times gross income or higher. For contractors, DTI is calculated on maintainable income, which is typically the average of the most recent two years of ABN income after business expenses.
If your income is reported as $180,000 per year after deductions, your maximum borrowing at six times DTI is $1,080,000 across all borrowings. If you already hold an owner-occupied loan of $600,000, your capacity for additional investment loan products is $480,000 before you breach the DTI threshold.
Fixed rate loans do not affect DTI calculations differently than variable loans, but the structure you choose impacts how quickly you can reduce debt and free up future borrowing capacity. A fully fixed interest-only loan does not reduce the principal balance or DTI. A variable split with offset and principal reduction does.
For contractors building a portfolio, maintaining access to liquid cash through offset and managing DTI through voluntary principal repayments on a variable split can mean the difference between qualifying for a second investment property within three years or waiting until the first loan term resets.
Structuring New Investment Loans From 1 July 2027
Under the Treasury Laws Amendment (Tax Reform No. 1) Act 2026, net rental losses on established residential properties acquired on or after 7:30pm AEST on 12 May 2026 are quarantined from 1 July 2027. Losses cannot be offset against contractor income. They can only be carried forward or offset against other residential rental income.
Eligible new builds acquired after that date retain full negative gearing. For contractors considering an investment purchase, the difference in after-tax holding cost between an established property and a new build can exceed $8,000 per year on a loan amount of $600,000 at current investor interest rates.
If you fix a loan on an established property and the monthly shortfall between rent and repayments is $1,200, you cannot claim that $14,400 annual loss against your contractor income from 1 July 2027. You carry it forward. If you purchase a new build, you continue to claim the full loss in the year it is incurred.
When evaluating whether to fix part or all of an investment loan on a post-12 May 2026 acquisition, the tax treatment of the holding cost should be factored into the cashflow analysis. A variable rate loan with offset gives you flexibility to pivot or sell without break costs if the quarantined loss becomes unsustainable.
Tax Deductibility of Fixed Rate Interest and Loan Purpose
Interest on an investment loan is deductible regardless of whether the rate is fixed or variable, provided the funds are used to acquire or hold an income-producing property. If you redraw extra repayments made on a fixed loan and use those funds for private purposes, the interest on the redrawn amount is not deductible.
Most fixed investment loan products do not offer redraw. This protects the integrity of the deductible loan balance but eliminates access to surplus repayments. If you do have redraw and you use it, you must track the purpose of every dollar redrawn to maintain deductibility.
The cleaner structure is a variable split with offset. Surplus cash sitting in offset is never repaid into the loan, so it remains accessible without affecting the deductible loan balance or creating a mixed-purpose loan.
For contractors managing ABN income and claimable expenses across multiple entities or trusts, maintaining a clear loan purpose trail is not optional. A fixed loan without redraw or a variable loan with offset both achieve that outcome. A fixed loan with redraw used for non-investment purposes does not.
When Full Fixed Makes Sense for Contractor Investors
A fully fixed investment loan works when your income is stable enough to service the repayments without relying on offset liquidity, and when you do not expect to sell or refinance the property within the fixed term.
In our experience, contractors with retainer arrangements or long-term government contracts can carry the repayment certainty of a full fixed structure without material cashflow risk. The absence of offset access is offset by the predictability of income.
Fully fixing also makes sense when rates are at or near a cyclical low and you want to lock in that cost for three to five years. The trade-off is reduced flexibility. If a project extends or a new opportunity requires capital, you cannot access funds already repaid, and you cannot exit without incurring potential break costs.
For most contractors, a split structure offers a more appropriate balance. You gain rate certainty on the majority of the debt while retaining liquidity through offset on the variable portion.
Call one of our team or book an appointment at a time that works for you. We will structure your investment loan options to align with your income cycle and portfolio strategy, and ensure your borrowing capacity is preserved for future growth.
Frequently Asked Questions
Can I make extra repayments on a fixed rate investment loan?
Most lenders allow between $10,000 and $30,000 in extra repayments per year on fixed rate investment loans without penalty. Once repaid, those funds are locked in the loan until the fixed term ends or you pay break costs to refinance.
What is a break cost on a fixed investment loan?
A break cost is the economic loss a lender incurs when you exit a fixed rate loan early. It is calculated as the difference between your fixed rate and the current wholesale rate for the remaining term. If rates have fallen, you reimburse the lender's funding loss.
Should contractors fix the entire investment loan or use a split structure?
A split structure preserves cashflow access by pairing a fixed portion for rate certainty with a variable portion linked to an offset account. Surplus contractor income can sit in offset, reducing interest on the variable split while remaining fully accessible during income gaps.
How do the new negative gearing rules affect fixed rate investment loans?
From 1 July 2027, rental losses on established properties acquired after 12 May 2026 are quarantined and cannot be offset against contractor income. Eligible new builds retain full negative gearing, which can reduce after-tax holding costs by over $8,000 per year on a typical loan.
Does fixing an interest-only investment loan affect tax deductions?
Interest remains fully deductible on a fixed interest-only investment loan, provided the loan is used to acquire or hold an income-producing property. Fixing the rate does not change the tax treatment of the interest expense.
