Understanding the basics of Investment Loan Optimisation

Getting your borrowing structure right from the start can make thousands of dollars of difference to what you keep each year.

Property investors in Runaway Bay often focus on finding the right property but overlook how loan structure affects cashflow, tax position and future borrowing capacity. The way you structure debt across multiple properties, choose between variable and fixed rates, and use features like offset accounts can directly change your holding costs and your ability to add to your portfolio later.

Should You Split Between Variable and Fixed Rates?

Splitting your loan between variable and fixed portions gives you some rate certainty without locking the entire amount away. A fixed portion protects part of your repayment from rate rises, while the variable portion keeps flexibility for extra repayments or redraw if your circumstances change.

Consider an investor who refinances a Runaway Bay unit with an outstanding balance around the area's typical unit price range. They fix half the loan for three years and leave the other half variable with an offset account. Rental income sits in the offset, reducing interest on the variable portion while the fixed portion provides a known repayment for budgeting. If rates drop, the variable portion benefits immediately. If rates rise, the fixed portion holds steady. That structure also avoids locking rental income into a loan where it can't be accessed without triggering break costs.

How Interest-Only Periods Affect Cashflow and Tax

An interest-only period means you pay only the interest charged each month, not any principal. Your loan balance stays the same, your repayments are lower, and every dollar of interest remains tax deductible as long as the property is rented or genuinely available for rent.

Interest-only suits investors focused on holding costs and tax deductions rather than paying down debt. The lower repayment improves cashflow, which can be directed to an offset account, another deposit, or kept as a buffer for vacancies and maintenance. Once the interest-only period ends, the loan reverts to principal and interest unless you apply to extend it. Lenders assess serviceability again at that point, and approvals depend on your income, other debts and the property's value at the time.

Does an Offset Account Work for Investment Loans?

An offset account can work well on the variable portion of an investment loan, but you need to weigh the benefit against the cost. Lenders typically charge a higher rate on loans with offset features compared to basic variable products. The interest saved by keeping funds in the offset needs to exceed that rate difference for the feature to add value.

Rental income is the obvious candidate for an offset account. Instead of sitting in a transaction account earning little or no interest, rental income held in an offset reduces the interest charged on your loan. That saves you money without affecting deductibility, because the interest you're charged on the reduced balance is still fully deductible. If you're holding savings for another deposit or a renovation, the offset keeps those funds accessible while reducing your interest cost in the meantime.

Structuring Loans Across Multiple Properties

When you own more than one property, keeping each loan separate gives you more control. Each property should have its own loan facility secured only against that property, rather than cross-securing multiple properties under one umbrella facility.

Separate loans mean you can sell one property and discharge its loan without affecting the others. Cross-securitisation ties your properties together, and selling one property usually requires lender consent and may trigger a full review of your entire lending position. Separate structures also make it clearer which interest and costs relate to which property, which matters for tax records and for calculating deductibility if one property is later converted to owner-occupied use.

Can You Use Equity Without Refinancing Everything?

You can access equity in one property to fund a deposit on another without refinancing your entire portfolio. A standalone equity loan or line of credit secured against the property with available equity lets you draw funds for the next purchase while leaving your existing loan untouched.

In our experience, this approach works well when your current loan has a competitive rate or features you want to keep. The equity facility sits separately, often on a higher rate, but only the amount you draw incurs interest. Once the new property settles, you can choose to keep the equity facility open as a buffer or roll it into the new loan depending on rate and feature comparison at the time.

What Happens to Your Borrowing Capacity as Your Portfolio Grows?

Lenders assess your borrowing capacity by comparing your income to all your current debts and living expenses, then testing whether you can service a new loan at a rate at least 3 percentage points above the actual product rate. As you add properties, rental income helps, but lenders typically shade that income to account for vacancies, management fees and maintenance. Most lenders apply a shading factor between 20 and 25 per cent, meaning they assess rental income at 75 to 80 per cent of the lease amount.

Your structure affects this calculation directly. Interest-only repayments on existing loans mean lower current commitments, which leaves more serviceability for the next purchase. An offset account with a healthy balance reduces the interest being charged, which can improve your actual cashflow and savings position even though it doesn't change the servicing test itself. Keeping loans separate and avoiding cross-securitisation also makes it easier to demonstrate your position clearly when applying for additional lending.

How Does Negative Gearing Fit Into Your Structure?

Negative gearing means your rental income is less than your holding costs, creating a loss you can offset against other income such as salary. For properties held before mid-May of the previous year, those losses remain fully deductible against all income. For properties acquired after that date, new rules apply from the next financial year, limiting where those losses can be used unless the property qualifies as a new build.

If you're acquiring established property now, your loan structure should account for the fact that losses will only offset other residential property income or gains from the next financial year onward. That makes it more important to structure for long-term capital growth and for cashflow sustainability without relying on an immediate tax refund. Interest-only periods and offset accounts become more valuable because they reduce your out-of-pocket holding cost without depending on cross-subsidisation from salary.

Refinancing to Optimise an Existing Portfolio

If your portfolio has grown over several years, your loans may be on different rates, with different features, and possibly cross-secured in ways that limit your flexibility. Refinancing lets you restructure everything at once, moving to a consistent framework that supports where you're heading next.

A refinance can separate cross-secured properties, shift older loans to current rates, add offset accounts where they're missing, and adjust interest-only periods to align with your current strategy. It's also the right time to release equity if you're planning another purchase, rather than waiting until you've found a property and need to move quickly. Refinancing does involve costs such as discharge fees, application fees and sometimes valuation fees, so the benefit needs to outweigh those costs over a realistic holding period.

Call one of our team or book an appointment at a time that works for you using our online booking page. We'll review your current position, compare your options across the lenders we work with, and help you structure your borrowing to support what you're building.

Frequently Asked Questions