Fixed Rate Investment Loans: How to Lock in Certainty

Locking in a fixed interest rate on an investment property loan protects your cash flow from rate movements.

Property investors in Mandurah and across Australia face a decision when structuring their investment property finance: whether to fix their interest rate and for how long. A fixed rate investment loan provides certainty over your repayments for a set period, which can make the difference between maintaining positive cash flow and dipping into your own funds each month. Unlike variable rates that move with the Reserve Bank's decisions, a fixed rate holds your repayments steady regardless of what happens in the broader economy.

What a Fixed Rate Investment Loan Offers Property Investors

A fixed rate investment loan locks your interest rate for a chosen period, typically between one and five years. Your repayments remain unchanged during this period, which means you can calculate your rental income against your loan costs with precision. Consider an investor who purchases a unit in Mandurah's Halls Head precinct for $450,000 with a 20% deposit, borrowing $360,000. If they fix at the current rate for three years on an interest only investment loan, their monthly repayment stays constant even if rates rise during that period. The rental income from the property, less expenses like body corporate fees common in coastal apartment complexes, can be measured against a known loan cost.

The protection works both ways. If rates fall after you fix, you remain locked at the higher rate unless you pay break costs to exit early. This is why the timing and term of your fixed period matters as much as the rate itself.

Interest Only Versus Principal and Interest on Fixed Rates

Most investors choose interest only repayments on their investment property loans because it maximises tax deductions and preserves cash flow. When you fix an interest only investment loan, your entire repayment is tax deductible as a claimable expense, and the amount you pay each month is typically lower than a principal and interest loan on the same amount. Using the previous example, an interest only loan on $360,000 at a fixed rate keeps the repayment focused solely on the interest component, leaving more of your rental income available for other purposes or to offset against your taxable income through negative gearing benefits.

Some investors opt for principal and interest to build equity faster, particularly if they're planning to leverage equity for their next purchase. The fixed rate still applies, but your repayment includes both components. The decision depends on whether your property investment strategy prioritises immediate cash flow or accelerated equity growth.

Fixed Rate Terms and Your Investment Timeline

The term you choose for your fixed period should align with your plans for the property and your view on rate movements. A one-year fix provides short-term certainty but requires you to make another decision quickly when it expires. A five-year fix locks you in for longer, which can be valuable if you're confident rates will rise, but limits your flexibility if your circumstances change.

In our experience, investors who plan to hold a property for passive income often fix for three years, which provides medium-term stability without excessive commitment. Those planning portfolio growth through equity release within a shorter timeframe might choose a two-year fix or split their loan between fixed and variable portions. The loan to value ratio (LVR) can also influence this decision. If you've borrowed at 80% LVR and paid Lenders Mortgage Insurance (LMI), you might want the certainty of fixed repayments while the property appreciates to a position where you can leverage equity without additional LMI on your next purchase.

Break Costs and Early Exit Scenarios

Fixed rate loans include break costs if you exit before the term ends. This cost reflects the difference between the rate you fixed at and the current wholesale rate the lender can achieve if they redeploy your funds. If rates have risen since you fixed, break costs are usually minimal or zero. If rates have fallen, break costs can be substantial.

Consider a scenario where an investor fixed $400,000 for five years but decides to sell the Mandurah property after two years due to a job relocation. If rates have dropped significantly in that period, the lender may charge break costs of several thousand dollars to compensate for their loss. Some lenders calculate this daily, others use a more favourable method. Understanding your lender's break cost formula before fixing is important, particularly for investors who might need to adjust their portfolio structure.

This is also relevant for investment loan refinance situations. If you find a significantly lower rate with another lender mid-term, you'll need to weigh the break costs against the potential savings from refinancing. Most investors only refinance a fixed loan early if the rate difference is substantial enough to justify the exit penalty.

Split Loans and Partial Fixed Rates

Many investors use a split loan structure, fixing a portion of their borrowing while keeping the remainder on a variable interest rate. This approach provides partial certainty while maintaining flexibility. You might fix 60% of your loan amount for three years and leave 40% variable. The variable portion allows you to make unlimited extra repayments without penalty and provides access to features like offset accounts, which aren't typically available on fixed portions.

For Mandurah investors holding properties in areas with seasonal rental demand, such as beachside locations with fluctuating vacancy rates during winter, the variable portion can absorb extra repayments when rental income is strong, while the fixed portion ensures your base repayment remains predictable year-round. Different lenders offer different split ratios and terms, so comparing investment loan options across multiple lenders reveals which structures suit your cash flow pattern.

Rate Discounts and Negotiation on Fixed Rates

The advertised fixed rate is rarely the final rate. Lenders offer rate discounts based on your loan amount, LVR, and relationship with them. An investor borrowing $500,000 at 75% LVR typically receives a better rate than someone borrowing $200,000 at 85% LVR requiring LMI. The size of your deposit and the equity position directly influence the rate discount available.

When comparing investment property rates, look beyond the headline figure to understand what discount applies to your specific scenario. A lender advertising a particular fixed rate might offer that only to borrowers with 30% deposits, while your 20% deposit attracts a different rate. This is where working with a broker who accesses investment loan options from banks and lenders across Australia provides value. They can identify which lenders offer the most favourable terms for your deposit size and borrowing amount, rather than you approaching each lender individually.

Call one of our team or book an appointment at a time that works for you to review your investment loan structure and determine whether fixing your rate aligns with your property investment strategy and cash flow requirements.

Frequently Asked Questions