Simple hacks to claim interest as a tax deduction

Investment loan interest is tax deductible when the borrowed funds are used to purchase income-producing assets.

The deduction applies to the interest portion of your loan repayments, not the principal, and is claimed against the income generated by those investments. For NSW residents earning above the average wage, this creates an opportunity to reduce taxable income by several thousand dollars annually while building an investment portfolio outside the family home.

How the ATO determines deductible interest

The ATO allows you to deduct interest on borrowings used to acquire income-producing investments. The connection between the loan and the investment must be direct and ongoing. If you borrow $50,000 against your home equity and transfer that amount into an investment account to purchase shares or managed funds, the interest on that $50,000 becomes deductible provided the investments produce assessable income such as dividends or distributions.

The loan purpose determines deductibility, not the security used. You can borrow against your home and still claim the interest as a deduction, provided the funds are used for investment purposes and never mixed with personal expenses. This distinction is central to debt recycling as a wealth-building approach.

Setting up a split loan structure for clear separation

A split loan structure separates your non-deductible home loan from the deductible investment loan at the bank level. Rather than redrawing from your existing home loan, you establish a new loan split secured against your property equity, with funds directed solely toward investment purchases.

Consider a homeowner in Sydney's Inner West with a $400,000 home loan balance and $150,000 in available equity. They establish a $100,000 investment loan split, leaving their original home loan untouched at $400,000. The $100,000 is transferred to a dedicated investment account, used to purchase exchange-traded funds, and the interest on that split becomes fully deductible. The home loan interest remains non-deductible. This separation makes record-keeping straightforward and ensures compliance during tax time.

Mixing funds between splits or using a redraw facility on your home loan for investment purposes creates problems with the ATO. The deduction is disallowed or reduced if personal and investment expenses flow through the same account.

Claiming the deduction through your tax return

You claim investment loan interest as a deduction in the 'Deductions' section of your individual tax return under the category for interest, dividend, and other investment income deductions. The deduction reduces your taxable income, not your tax payable directly, so the benefit depends on your marginal tax rate.

If you pay $6,000 in interest on an investment loan and your marginal tax rate is 37%, the deduction reduces your tax payable by approximately $2,220. You will need loan statements showing the interest charged during the financial year and records confirming the borrowed funds were used exclusively for investment purposes. Keep these records for at least five years in case of an audit.

For NSW residents using debt recycling to convert home loan debt into investment debt progressively, each dollar of interest switches from non-deductible to deductible as the strategy proceeds. Over time, this increases the total deduction claimed and accelerates the home loan repayment without reducing cashflow.

What happens if you sell the investment

The interest remains deductible after you sell the investment, provided the loan was originally used for an income-producing purpose and you have not used the sale proceeds to pay down the investment loan. If you sell shares purchased with your investment loan and leave the loan balance unchanged, the interest stays deductible while you hold cash or reinvest the proceeds.

Once you use the sale proceeds to reduce the investment loan balance, the deductible portion of the loan reduces accordingly. If you had a $100,000 investment loan, sold the shares for $120,000, and paid $50,000 off the loan, only the remaining $50,000 balance generates deductible interest going forward. Timing the repayment of investment debt versus non-deductible home loan debt requires careful planning if you want to preserve the tax benefit.

Keeping compliant records for the ATO

The ATO expects clear documentation linking each dollar borrowed to the investment it funded. This means separate bank accounts, separate loan splits, and statements showing the flow of funds from the investment loan to the investment platform or property settlement.

In a scenario where a couple in the Northern Beaches borrows $80,000 to invest in a diversified portfolio, they should maintain a dedicated offset or transaction account linked only to the investment loan split. All dividends and distributions are deposited into this account, and all investment-related expenses are paid from it. Interest statements, brokerage receipts, and dividend statements are saved digitally and matched to the loan at tax time. If questioned, they can show the ATO an unbroken chain from loan drawdown to investment purchase to income received.

Avoid using the investment loan for any personal expenses, even temporarily. A single transaction for groceries or a holiday breaks the deductibility of that portion of the loan and complicates your tax position.

How debt recycling increases the deduction over time

Debt recycling involves using investment income or surplus cashflow to pay down your non-deductible home loan, then redrawing that amount as a new investment loan to purchase additional assets. Each cycle converts more non-deductible debt into deductible debt, increasing your annual interest deduction while keeping total debt stable.

A homeowner with a $500,000 home loan and no investment debt might start by establishing a $50,000 investment loan to purchase shares. After 12 months, dividends and additional repayments reduce the home loan by another $30,000, which is then redrawn and reinvested. The deductible loan balance grows to $80,000, increasing the annual interest deduction from approximately $2,500 to $4,000, depending on the interest rate. Over a decade, this approach can shift several hundred thousand dollars from non-deductible to deductible, reducing taxable income substantially each year.

The strategy works because the tax deduction improves cashflow, making it more sustainable to maintain the same level of debt while building an investment portfolio outside the family home.

Common mistakes that reduce or disallow the deduction

Using a redraw facility on your home loan instead of a separate split is the most common error. Redraw facilities mix repaid principal with new borrowings, making it difficult to prove to the ATO that specific funds were used exclusively for investment. Offset accounts linked to the home loan do not create this problem, but redrawing from the home loan itself does.

Another mistake is paying investment expenses from your personal account or home loan offset. If you pay brokerage fees, account fees, or adviser fees from a non-investment account, you must track those separately and claim them as a distinct deduction. Mixing these payments reduces the clarity of your records and increases the risk of an audit adjustment.

Capitalising interest by adding it to the loan balance instead of paying it from cashflow does not prevent the deduction, but it does increase the complexity of your records. The ATO allows deductions for capitalised interest, but only if the loan remains exclusively for investment purposes.

Does the deduction apply to property investments differently

Investment property loans work the same way as loans for shares or managed funds. The interest is deductible if the property produces rental income, and the loan must be used exclusively to purchase, build, or improve the investment property. You cannot claim interest on a loan used to buy an investment property if you later move into it and stop charging rent.

For NSW property investors considering debt recycling as a way to build a portfolio, the structure remains identical. You establish a separate loan split against your home equity, use those funds to cover the deposit and purchase costs on an investment property, and claim the interest as a deduction. Rental income is deposited into a dedicated account, and all property expenses are paid from that account to maintain clear records.

Negative gearing, where the investment property costs more to hold than it generates in rent, increases the value of the interest deduction because it offsets other taxable income. Debt recycling accelerates this by converting non-deductible home debt into deductible property debt faster than saving for a deposit would allow.

Call one of our team or book an appointment at a time that works for you to discuss how to structure your loans for maximum deductibility and ensure your records meet ATO requirements from the start.

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