Unlock the secrets to Investment Loan Optimisation

What Investment Loan Optimisation Actually Involves

Investment loan optimisation means structuring your borrowing so that you pay less interest over time, maintain access to equity as your portfolio grows, and reduce the risk of being locked into a product that no longer suits your strategy. It is not simply chasing the lowest advertised rate.

Consider a buyer holding two properties in South Perth who refinanced both loans into a single facility three years ago to access a rate discount. The combined loan now sits at 75 per cent loan to value ratio, but because both properties secure the one loan, the investor cannot access equity in either property without refinancing the entire facility. When an opportunity arises to purchase a third property, the cost and delay of refinancing both loans, plus the fact that one lender now holds all the security, limits the investor's options. Had the loans been split across two lenders with separate securities, equity in the higher-growth property could have been released without disturbing the other loan.

This is the difference between a loan that looks good on a rate comparison website and a loan structure that supports portfolio growth. Optimisation addresses how your loans are split, which features you pay for, how security is allocated, and whether your current structure will still work under the negative gearing and capital gains tax changes taking effect from 1 July 2027.

How Loan Splitting Preserves Equity Access

Splitting your borrowing across multiple loan accounts or lenders allows you to release equity in one property without refinancing your entire portfolio. Each loan is secured against a specific property, so when you want to access growth in one asset, only that loan needs to be varied.

In a scenario where an investor owns a unit in Como and a townhouse in Waterford, both properties have increased in value but the Como unit has performed better due to its proximity to the Swan River and Angelo Street cafe precinct. If both properties secure a single loan, the investor must refinance the entire debt to access equity in the Como unit. If the loans are split, the investor can retain the existing Waterford loan and vary or refinance only the Como loan, reducing application costs, valuation fees and the risk of losing a discounted rate on the Waterford property.

Loan splitting also reduces cross-collateralisation risk. When multiple properties secure one loan and you want to sell a property, the lender must consent to release that security. If the sale reduces the lender's total security below their required loan to value ratio, they may refuse consent or require you to pay down the loan before releasing the property. Separate loans remove that dependency.

Interest Only or Principal and Interest for Investment Property

Interest only repayments reduce your monthly outlay and preserve cash flow, which is useful when rental income does not cover all holding costs or when you want to direct surplus cash toward acquiring additional properties. Principal and interest repayments build equity faster and reduce your total interest cost over the life of the loan.

The choice depends on whether you are prioritising cash flow for portfolio growth or debt reduction for long-term security. Many investors start with interest only during the acquisition phase and switch to principal and interest once the portfolio is established or when income increases.

Under the new negative gearing rules, residential rental losses on properties acquired after 7:30pm AEST on 12 May 2026 cannot be offset against salary or wages from 1 July 2027 unless the property is an eligible new build. Interest deductions are not removed, but if your interest and other expenses exceed your rental income, that loss can only be offset against other residential rental income or carried forward. This makes cash flow management more important. An interest only loan may no longer be viable if you cannot absorb the rental loss within your residential rental income, and switching to principal and interest will increase your monthly repayment further.

If you are holding properties acquired before 12 May 2026, or properties under contract at that time, existing negative gearing rules continue to apply until you sell. Interest only may still be appropriate for those properties if your strategy relies on offsetting losses against employment income.

Variable or Fixed Rate for Investment Loans

Variable rate investment loans allow you to make extra repayments, redraw funds and access offset accounts without penalty. Fixed rate investment loans lock in your rate for a set period, usually one to five years, but restrict additional repayments and usually do not offer offset accounts. If you exit a fixed rate loan early, you may be liable for break costs.

For investors who plan to refinance, access equity or sell within the next few years, a variable rate provides flexibility. For investors who want certainty over repayments and do not plan to adjust their loan structure, a fixed rate may be suitable. Splitting your loan between variable and fixed allows you to lock in part of your rate while retaining access to features on the variable portion.

If you are acquiring an investment property in South Perth, where rental vacancy rates have remained low due to demand from professionals working in the Perth CBD and medical precinct, a variable rate loan with offset allows you to park rental income and other savings against the loan balance, reducing the interest charged. This is particularly useful if you are managing rental income across multiple properties and want the flexibility to move funds between accounts.

Loan Features That Reduce Interest and Increase Flexibility

An offset account linked to your investment loan reduces the interest charged on your loan balance by the amount held in the offset. If your loan balance is $400,000 and you hold $30,000 in the offset, you are charged interest on $370,000. The offset balance remains accessible, so you do not sacrifice liquidity to reduce interest.

A redraw facility allows you to make extra repayments and withdraw them later if needed. Unlike an offset, redraw balances are not kept in a separate account and some lenders impose withdrawal limits or delays. Offset accounts provide more immediate access and do not affect your loan balance for tax purposes, which is why they are generally preferred for investment loans.

Some lenders charge monthly fees for offset accounts or limit the number of offset accounts per loan. When comparing investment loan options, check whether offset accounts are included and whether there are limits on how many properties can be linked to a single loan.

When Refinancing an Investment Loan Makes Sense

Refinancing an investment loan is worthwhile when the interest saving or structural benefit exceeds the cost of refinancing. Refinancing costs typically include application fees, valuation fees, discharge fees on your existing loan and settlement fees. Some lenders offer refinance packages that waive or rebate certain fees.

If your current lender is not offering you the same rate discount available to new customers, or if your loan lacks features you now need, refinancing may be appropriate. In our experience, investors who refinanced in the past two years often did so to consolidate debt, access equity for further purchases, or move away from lenders that had reduced serviceability or tightened policies on interest only extensions.

Refinancing also allows you to separate cross-collateralised loans. If your existing lender holds multiple properties as security for a single loan, refinancing each property with a different lender removes that constraint and allows independent access to equity in each property.

Before refinancing, confirm that your current loan structure will support your plans over the next three to five years. If you expect to acquire more properties, sell an existing property or significantly change your income, your loan structure should accommodate those changes without requiring another refinance.

How Loan to Value Ratio Affects Borrowing Capacity and Costs

Your loan to value ratio determines how much you can borrow and whether you will pay Lenders Mortgage Insurance. LMI is a one-off premium charged when your loan exceeds 80 per cent of the property value. It protects the lender, not you, but allows you to borrow with a smaller deposit.

If you are leveraging equity in an existing property to fund a deposit on a new investment property, the LVR on each property determines how much equity you can access and whether LMI applies. For example, if you own a property in South Perth valued at $700,000 with a loan of $400,000, your current LVR is approximately 57 per cent. Borrowing up to 80 per cent LVR on that property would give you access to $560,000 in total lending, releasing $160,000 in equity before LMI applies. If you borrow above 80 per cent, LMI will be charged on the new loan amount.

LMI premiums increase sharply above 90 per cent LVR. For investors with multiple properties, keeping each property at or below 80 per cent LVR avoids LMI and preserves borrowing capacity for future purchases. Check your current LVR on each property and whether releasing equity will push you into an LMI threshold.

Using Equity to Fund Deposits Without Selling Property

Equity is the difference between what your property is worth and what you owe on it. You can borrow against that equity to fund a deposit on another property without selling your existing property. This allows you to grow your portfolio while retaining the rental income and capital growth potential of your current holdings.

To access equity, your lender will revalue your property and calculate how much additional borrowing they will approve based on your current LVR and serviceability. If you want to avoid LMI, you will typically be limited to borrowing up to 80 per cent of the revalued property.

Accessing equity requires either increasing your current loan or establishing a separate line of credit secured against the property. A line of credit provides flexibility because you only draw down and pay interest on the amount you use, but interest rates on lines of credit are typically higher than standard variable rates. Most investors use a standard loan top-up rather than a line of credit unless they need to draw funds progressively.

Structuring Loans to Minimise Cross-Collateralisation

Cross-collateralisation occurs when one loan is secured by multiple properties. It is common when you borrow from the same lender to purchase a second property and that lender takes security over both properties for both loans. While this may simplify the application process, it restricts your ability to deal with each property independently.

If you want to sell one property, the lender must agree to release it from the security pool. If selling that property leaves the remaining security below the lender's required LVR, the lender may refuse consent or require you to pay down the loan. You also cannot refinance one property without refinancing both.

To avoid cross-collateralisation, use separate lenders for each property or insist that your current lender provides separate loan contracts with individual security. This requires clear instruction at the time of application and may reduce the rate discount the lender is willing to offer, but it provides independence when you want to sell, refinance or access equity in a single property.

Preparing for the Negative Gearing and Capital Gains Tax Changes

From 1 July 2027, rental losses on residential properties acquired after 12 May 2026 can only be offset against other residential rental income or carried forward. They cannot be offset against salary, wages or other non-residential income unless the property is an eligible new build. Interest on your investment loan remains deductible, but if your total expenses exceed your rental income, that loss is quarantined.

If you are acquiring property now, this affects your cash flow forecasting. You will need sufficient rental income across your portfolio to absorb losses, or sufficient other income to cover the shortfall without the tax benefit of offsetting losses against salary. This makes interest only loans less attractive unless your rental income is strong, because you will not receive a tax benefit from the rental loss and your cash flow will be negative.

For capital gains, the 50 per cent discount for assets acquired after 1 July 2027 is replaced with cost base indexation and a minimum 30 per cent tax rate on real gains. If you acquire an eligible new build, you can elect between the 50 per cent discount and indexation, giving you flexibility depending on your circumstances at the time of sale. Properties you already own, or acquire before 1 July 2027, remain under current rules for gains accrued before that date.

If you are refinancing, confirm with your broker whether your loan structure accommodates multiple properties acquired under different tax treatments. You may want to separate loans by acquisition date so that loans on grandfathered properties remain distinct from loans on properties subject to the new rules.

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