Fixed, Variable, or Split: Choosing Your Investment Loan

The structure you choose for your investment loan determines how much control you have when rates change and how much flexibility you retain if your rental income drops or vacancy rate spikes.

Property investors in Perth and across Western Australia are facing an unusual crossroad. Variable rates have moved significantly in recent cycles, while fixed options lock in certainty but remove your ability to make extra repayments or release equity without penalty. The decision between fixed, variable, and split structures affects not just your monthly repayment, but your capacity to respond when tenants leave, when you want to access equity for your next purchase, or when you need to refinance to secure better investor interest rates.

Variable Rate Investment Loans: Full Flexibility With Rate Exposure

A variable rate investment loan adjusts with market movements and gives you unlimited ability to make extra repayments, redraw funds, and access equity without break costs. Your interest rate will move up or down based on Reserve Bank decisions and lender pricing, which means your repayments can change during the life of the loan.

Consider an investor who purchased a rental property in Joondalup with a variable rate loan at 80% loan to value ratio. When their tenants gave notice, they could redraw $15,000 from offset funds to cover the mortgage during a three-month vacancy without applying for additional credit. When rental demand returned and they secured new tenants at a higher weekly rate, they redirected that additional passive income back into the loan to reduce the principal faster. Variable structures support this kind of responsive management because there are no restrictions on repayment timing or amounts.

The downside sits with rate exposure. If variable interest rates increase by even half a percent, your monthly cost rises immediately. For an investment loan amount of $500,000, that movement adds roughly $200 per month to your repayment. If your rental income barely covers the mortgage and claimable expenses, you may need to fund the shortfall from your own pocket while waiting for lease renewal to adjust rent.

Variable rates typically come with offset accounts and redraw facilities, which become valuable when managing negative gearing benefits or building a buffer for unexpected property costs like body corporate levies or urgent maintenance.

Fixed Rate Investment Loans: Certainty With Restrictions

A fixed interest rate locks your repayment amount for a set period, usually between one and five years, regardless of what happens to the broader market. You know exactly what your mortgage costs each month, which makes budgeting simpler when you are calculating investment loan repayments against expected rental income.

In our experience, investors who choose fixed structures do so because they want protection against rate rises during a specific period when their cash flow is tight or when they expect rates to climb. If you fix at a lower rate and the market moves up, you continue paying the locked rate and avoid the increase. If rates fall, you remain locked at the higher rate until the fixed term ends.

The restriction comes with prepayment limits. Most fixed rate products allow only minimal extra repayments, often capped at $10,000 per year. If you want to pay down the loan faster using surplus rental income or release equity to fund another deposit, you will face break costs. These costs can run into thousands of dollars depending on how much rates have moved since you locked in and how long remains on your fixed term.

Fixed loans rarely include offset accounts, which removes one of the main tools investors use to manage cash flow and maximise tax deductions. The interest you pay remains constant, but you lose the ability to reduce it by parking surplus funds in an offset.

If you are purchasing an investment property with tight margins and want absolute certainty on what the loan costs during the initial settlement period or lease term, a fixed structure provides that. You sacrifice flexibility to gain predictability.

Split Loan Structures: Blending Certainty and Control

A split loan divides your total borrowing between fixed and variable portions, letting you lock in part of your repayment while keeping access to flexibility on the rest. You choose the split ratio based on how much certainty you want versus how much control you need to manage the property as circumstances change.

As an example, an investor with a $600,000 property investment loan might fix $400,000 at a set rate for three years and leave $200,000 on a variable rate with offset access. The fixed portion protects two-thirds of the loan from rate rises, while the variable portion allows unlimited extra repayments, redraw, and equity release without penalty. If vacancy rate increases or rental income drops, they can redraw from the variable portion to cover the shortfall. If they want to leverage equity for portfolio growth, they can access it through the variable side without triggering break costs.

Split structures let you respond to changing conditions without gambling your entire loan amount on one outcome. If rates rise, the fixed portion shields part of your repayment. If rates fall, the variable portion benefits immediately and you retain the ability to make extra repayments or use offset funds to reduce taxable interest.

The downside involves administration. You manage two loan accounts with separate statements, and your lender may charge two sets of fees. Some lenders also require minimum amounts on each side of the split, typically $50,000 or more, which limits how you can divide smaller investment loan options.

When structuring a split, align the fixed portion with your expected holding period or the timeframe you want protection. If you plan to hold the property for five years before selling or refinancing, fixing a portion for three to five years gives you certainty during that window while keeping enough variable balance to manage cash flow and access equity if needed.

Interest Only Versus Principal and Interest on Investment Loans

Regardless of whether you choose fixed, variable, or split, you also decide between interest only repayments or principal and interest. Interest only investment loans reduce your monthly repayment because you are not paying down the loan balance, which can improve cash flow during the early years when rental income may not cover all costs including Lenders Mortgage Insurance, stamp duty, and agent fees.

Most investors in Western Australia choose interest only periods of five years to maximise tax deductions and redirect surplus income toward other investments or deposits for additional properties. Once the interest only period ends, the loan converts to principal and interest, and your repayment increases because you begin reducing the loan amount.

Interest only works when your property investment strategy focuses on capital growth and portfolio growth rather than paying down debt quickly. You borrow more over the life of the loan compared to principal and interest, but you retain cash flexibility and potentially build wealth through multiple properties rather than funnelling all surplus funds into one mortgage.

If building equity quickly matters more than cash flow or if you prefer to reduce your debt as rental income grows, principal and interest repayments suit that approach. Your monthly cost is higher, but you reduce the loan balance with every payment and your loan to value ratio improves over time.

How to Choose Between Fixed, Variable, and Split for Your Investment Property Finance

Your choice depends on three factors: how certain you need your repayment to be, how much flexibility you need to manage the property, and what you plan to do with the property over the next few years.

If you have minimal cash reserves and cannot absorb repayment increases, fixing part or all of the loan protects you during a specific period. If you are managing multiple properties, need to access equity for your next purchase, or want to use offset accounts to reduce interest and manage tax, variable or split structures give you that control.

Investors in suburbs across Perth including Baldivis, Ellenbrook, and Butler often face higher vacancy rate fluctuations compared to inner-city areas, which makes access to redraw and offset facilities more valuable. If your tenant leaves and you need three months to secure a replacement, pulling funds from offset or redraw keeps the mortgage covered without applying for additional credit or selling investments.

If you are buying an investment property with plans to refinance within two years to access equity or consolidate debt, locking into a long fixed term creates break cost risk. A variable or short-term fixed structure keeps your options open without penalty.

Talk through your property investment strategy with someone who can model different scenarios based on your specific investor deposit, expected rental income, and timeline. The structure that suits an investor holding one property for ten years differs from someone building a portfolio of three properties over five years.

Call one of our team or book an appointment at a time that works for you to review your investment loan application and work through which structure aligns with your goals and cash flow across Western Australia.

Frequently Asked Questions