Avoid These 5 Fixed Rate Investment Loan Mistakes

A fixed rate on an investment loan offers rate certainty, but the structure you choose now will determine whether that certainty becomes an advantage or a constraint.

Investors across Baulkham Hills, Castle Hill and Northmead are weighing fixed rate options as part of their broader property strategy, particularly with negative gearing changes taking effect from 1 July 2027. The decision isn't just about securing a rate. It's about matching that rate to your cashflow needs, tax planning, and the likelihood you'll need to refinance or restructure before the fixed term ends.

Locking in the Full Loan Amount Without a Split

Fixing your entire investment loan amount limits your ability to make additional repayments or access redraw without penalty. Consider an investor who acquired a property in Castle Hill under a three-year fixed term at 5.8 per cent. Eighteen months later, they identified a second investment opportunity and needed to refinance to release equity. Break costs exceeded $11,000, erasing most of the benefit they'd gained from the fixed rate.

A split structure, where part of the loan remains variable and part is fixed, preserves flexibility. The variable portion allows extra repayments, redraw access, and penalty-free refinancing if your circumstances change. In our experience, investors who retain at least 30 to 40 per cent of the loan on a variable rate maintain enough room to adapt without triggering break costs on the entire balance.

Choosing a Fixed Term That Doesn't Align With Your Tax Position

The new negative gearing rules create a timeline that matters. Properties acquired from 7:30pm on 12 May 2026 onward can only offset rental losses against other residential rental income or future gains unless they qualify as eligible new builds. If you're acquiring an established property and expecting it to move into positive cashflow within two years, a five-year fixed term may not suit your tax planning.

Investors holding established properties acquired before that date can still deduct losses against salary or other income until they sell. If you're in that position and your fixed term extends beyond the point where the property becomes cashflow positive, you lose the ability to switch to interest-only or adjust the structure to suit a change in strategy. Matching the fixed term to your expected cashflow profile avoids locking in a repayment structure that no longer serves you.

Overlooking Interest-Only Fixed Options

Not all lenders offer interest-only terms on fixed rate investment loans, and those that do often limit the period to one or two years within a longer fixed term. If your strategy relies on maximising tax-deductible interest and directing surplus cashflow into other investments or offset accounts linked to non-deductible debt, a principal and interest fixed loan works against that.

An investor purchasing a unit in Baulkham Hills with a loan to value ratio of 75 per cent might pay an additional $520 per month on a principal and interest structure compared to interest-only at current variable rates. Over three years, that's more than $18,000 in principal repayments on a loan where the interest remains fully deductible. If that investor also holds owner-occupied debt at a higher rate, the cashflow saved on an interest-only investment loan could have reduced non-deductible debt faster.

Assuming Fixed Rates Are Always Lower

Fixed rates on investment loans are typically higher than equivalent variable rates at the time you lock them in. The value lies in certainty, not cost. Lenders price fixed terms based on wholesale swap rates and their view of future funding costs, which means the fixed rate reflects an expectation of where variable rates might move over that period.

If variable rates fall or remain flat, you'll pay more under a fixed structure and may face break costs if you try to exit early. If rates rise, the fixed loan insulates you from those increases. The decision should be driven by your tolerance for repayment variation and your ability to absorb rate rises without compromising other financial commitments, not by the assumption that fixing always saves money.

Ignoring the Impact of Rate Discounts on Refinancing

Rate discounts on investment loans vary widely between lenders, and those discounts are often renegotiated at refinance. If you fix with a lender offering a modest discount, you may find that competitive variable rates from other lenders sit below your fixed rate once your term expires. This becomes a problem if your fixed term ends during a period when you're managing other portfolio activity or personal commitments and don't have time to refinance immediately.

Lenders typically revert fixed rate loans to a standard variable rate at the end of the term, which is almost never competitive. Without proactive refinancing or renegotiation, you can move from a discounted fixed rate to a revert rate that's 0.5 to 1 per cent higher than what you could access elsewhere. For investors in the Hills District managing multiple properties, that difference compounds quickly. Setting a reminder six months before your fixed term ends, or engaging a broker to manage the transition, ensures you don't lose ground through inaction.

Failing to Factor in Portfolio Growth and Future Borrowing

Fixed rate loans can limit your borrowing capacity when you apply for additional finance. Lenders assess your serviceability based on the higher of the actual rate and a buffer, typically 3 percentage points above the product rate under APRA's current settings. A fixed rate loan at 5.8 per cent is assessed at 8.8 per cent. If you're planning to acquire a second property within the next 12 to 24 months, fixing a large portion of your existing investment loan can reduce the amount you're able to borrow for the next purchase.

This is particularly relevant for investors navigating the debt-to-income cap introduced in February 2026. Lenders can only allocate 20 per cent of new investor lending to borrowers with a debt-to-income ratio of 6 times or greater. If your fixed loan pushes your assessed serviceability close to that threshold, you may find yourself unable to access finance for a subsequent acquisition even if your actual cashflow supports it. Keeping part of your loan variable, or choosing a shorter fixed term, preserves borrowing headroom without sacrificing all rate certainty.

Fixed rates serve a purpose when they're matched to your cashflow, tax position, and portfolio timeline. The structure you choose now should support the decisions you're likely to make over the next two to five years, not constrain them. If your current investment loan setup doesn't reflect where your portfolio is heading, or if you're unsure how the new tax measures affect your refinancing options, call one of our team or book an appointment at a time that works for you.

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