Investment property loans vs owner-occupier loans — key differences and what to compare

If you are weighing up an investment property purchase against a home you intend to live in, the loan you apply for sits on a different set of lender rules, pricing and tax treatment. The key difference is that investment loans are priced higher because regulators and lenders view them as riskier. Lenders also assess your ability to service the loan differently, often factoring in rental income but applying larger buffers and stricter living-expense tests.

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Rate spreads between investor and owner-occupier loans

Reserve Bank of Australia data for May 2026 shows the average interest rate on outstanding owner-occupier loans was 6.20%, while outstanding investment loans averaged 6.43%. The gap is even wider for interest-only loans: the average outstanding owner-occupier interest-only rate was 6.85% against 6.56% for investment interest-only loans. On the new-loan side the pattern holds, with investment new loans averaging 6.39% against 6.22% for owner-occupiers. These spreads are consistent with the higher capital charges that APRA’s prudential framework applies to investment lending.

Serviceability: how lenders assess investment borrowing power

APRA sets the prudential rules that banks and other authorised deposit-taking institutions follow when assessing home loan applications. For investment loans, lenders typically apply a minimum floor rate or an interest-rate buffer above the actual loan rate — often 3 percentage points — to test whether you could still afford repayments if rates rose. Rental income is usually shaded (only 70%–80% of the weekly rent is counted), and any existing debts, including the owner-occupied mortgage, are taken at their actual repayments. The effect is that the maximum borrowing amount for an investment property is often lower than for an owner-occupied home on the same income.

Loan-to-value ratio ceilings

Investment loans attract lower maximum LVRs at most lenders. While an owner-occupier may borrow up to 95% (with lenders mortgage insurance), the same lender will often cap the LVR on an investment purchase at 90%, and lower still if you want an interest-only term. A larger deposit — or more equity in an existing property — becomes necessary.

Interest-only and principal-and-interest repayment choices

Interest-only repayments are far more common among investors. The RBA’s May 2026 figures show that for outstanding investment loans the average principal-and-interest rate was 6.38% and the average interest-only rate was 6.56%, a modest premium. The tax treatment of interest makes interest-only an attractive option for some investors because the interest component can be claimed as a deduction against rental income, while principal repayments cannot.

Tax implications to compare

Investment loans allow the interest charged (and some other borrowing costs) to be claimed as a tax deduction. Owner-occupied loans do not. This tax asymmetry means the after-tax cost of an investment loan can be noticeably lower than the headline rate suggests, especially for investors in higher marginal tax brackets. However, any redraw or offset arrangement that reduces the loan balance for a period also reduces the deductible interest, so structuring the loan correctly is important. Depreciation schedules, capital works deductions and the eventual capital gains tax obligation also form part of the investment property equation, but they sit outside the loan itself.

Features investors should compare

Beyond the headline rate, investors should compare:

• Offset and redraw: A fully transactional offset account can park rental income and personal savings to reduce interest while keeping the loan balance intact for future deductions.
• Interest-only term and expiry: The length of the interest-only period and the step-up in repayments when it switches to principal-and-interest can be significant.
• Portfolio limits: Many lenders limit the total number of investment properties you can have, the total exposure, or the share of rental income they will accept.
• Fixed-rate break costs: If you fix part of the investment loan, ensure you understand the economic cost of breaking the fixed term early — it can be far higher than for owner-occupier loans.
• Cross-collateralisation: Avoid tying multiple properties to the same lender unless you fully understand the equity-lock risk.

Using calculators to model the numbers

OzLoan’s free calculators let you run side-by-side comparisons without submitting personal details. The Borrowing Capacity Estimator applies the APRA 3% buffer and can highlight the difference between an owner-occupied and an investment scenario. The Interest-Only vs Principal-and-Interest Comparison calculator shows the step-up shock when the interest-only term ends. The Offset Account Savings Calculator demonstrates how parking surplus cash can shorten an investment loan term.

Where to go next

Start by modelling your borrowing power under both scenarios with the calculators, then compare lender rates and features with that baseline in mind. Because every couple of basis points on an investment loan amplifies the effect over a decades-long term, the rate spread and tax treatment quickly become the two most important dials to adjust. OzLoan’s research compares policy changes across the market, but any decision should be weighed against your own financial position.