Common Mistakes with Investment Loan Structures

The Structure Decision That Locked Out a Second Purchase

Your loan structure determines whether you can access equity later without refinancing every property you own. Consider a buyer who took out a $600,000 loan for a Richmond apartment in early 2025, structured as a single facility with an offset account holding $40,000. Eighteen months later, the property had gained $80,000 in value and they wanted to access equity for a second purchase. The problem surfaced immediately. The offset account balance sat against the entire loan, reducing the recorded debt to $560,000 for tax purposes. To release equity, the lender required the entire loan to be revalued and the offset cleared, which meant recalculating interest deductions and losing the cash buffer they'd built deliberately. The alternative was a standalone top-up loan at a higher rate because the combined LVR pushed past 80 per cent. The purchase fell through.

A split structure, where the investment loan sat in one facility and any future equity release sat in another from day one, would have allowed the second drawdown without touching the original loan or its deductibility.

Interest Only or Principal and Interest

Interest-only repayments keep your monthly outgoings lower and preserve cash for additional deposits or other investments. Principal-and-interest repayments reduce your loan balance over time but cost more each month and may limit your ability to deploy capital elsewhere. The choice depends on whether you're prioritising cash flow now or debt reduction over the loan term.

For investment purposes, interest-only periods typically run for five years, after which the loan reverts to principal and interest unless you apply to extend. Most lenders allow one or two extensions, but approval depends on your serviceability at the time and the property's LVR. Under APS 112, a loan with an interest-only period longer than five years and an LVR above 80 per cent is classified as non-standard, which increases the lender's capital requirement and usually results in a higher rate or outright decline.

Interest-only suits investors focused on acquiring multiple properties in a compressed timeframe. Lower repayments mean more borrowing capacity remains available, which matters when your borrowing capacity determines how many properties you can hold simultaneously. Principal and interest suits those building a single-property portfolio or nearing retirement, where paying down debt becomes the priority.

Fixed Rate, Variable Rate or Split

Variable rates move with the market and give you full access to offset accounts, unlimited extra repayments and the ability to redraw or refinance without break costs. Fixed rates lock your repayment amount for a set period, typically one to five years, but charge you an exit fee if you repay early, sell the property or refinance before the term ends. Break costs are calculated based on the difference between your fixed rate and the lender's current wholesale funding cost, multiplied by the outstanding term. In a falling rate environment, break costs can run to tens of thousands of dollars.

A split structure, where part of your loan sits on a fixed rate and part on variable, gives you rate protection on one portion while keeping flexibility on the other. Splits are particularly relevant for investors holding multiple properties, where one loan might fund a high-yield regional property and another a low-yield inner-city asset. You can fix the regional loan to protect cash flow and keep the inner-city loan variable to allow offset use and future equity access.

Splits also reduce refinancing friction. If rates drop and you want to exit your fixed portion, you can refinance the variable portion to a new lender while leaving the fixed portion in place until it expires. The alternative is paying the break cost upfront or waiting until the fixed term ends, by which time the rate opportunity may have passed.

Standalone Loan or Cross-Collateralised Portfolio

A standalone loan uses one property as security for one loan only. A cross-collateralised structure uses multiple properties as security for multiple loans under a single mortgage document. Cross-collateralisation is common when you refinance an existing owner-occupied property and an investment property together, or when you use equity from one property to fund the deposit on another without changing lenders.

The appeal is convenience. One application, one valuation fee, one settlement. The cost is control. If you want to sell one property, the lender must agree to release it from the mortgage, which requires a revaluation of the remaining properties and confirmation that your LVR and serviceability still meet policy. If either has deteriorated, the lender can refuse the release or require you to pay down debt before proceeding. If you want to refinance one loan to access a lower rate, you must refinance the entire portfolio or pay discharge fees and break costs on the others.

In our experience, investors who cross-collateralise early in their portfolio growth find themselves stuck with the same lender for years, unable to move individual properties to access better rates or features. Keeping loans standalone adds complexity at the start but preserves the option to move each property independently as your circumstances and the market change.

Offset Accounts and Interest Deductibility

An offset account reduces the interest you pay without reducing the loan balance for tax purposes. If you hold a $500,000 investment loan and keep $30,000 in a linked offset account, you pay interest on $470,000 but still claim deductions on the full $500,000. This is useful if you expect to use the offset funds later for personal purposes, because the deductibility of your investment loan remains intact.

The structure breaks down if you withdraw offset funds to pay down the same investment loan and later redraw. Redrawing from an investment loan for personal use creates a mixed-purpose loan, where part of the balance is deductible and part is not. The ATO requires you to apportion interest deductions based on the purpose of each drawdown, which becomes an administrative burden and increases the risk of error.

If you plan to use offset funds for a future investment purchase, keep them in the offset account and draw a new loan facility for the next property. That keeps each loan's purpose clear and each interest deduction quarantined.

Loan Structure and Negative Gearing Changes from July 2027

From the 2027-28 income year, losses on established residential investment properties acquired after 12 May 2026 can only be offset against other residential property income, not against salary or wages. Properties held at 12 May 2026 and new builds acquired after that date retain full negative gearing. These changes make loan structure more important for buyers who purchased after the cut-off date, particularly those planning to build a portfolio where some properties generate positive cash flow and others generate losses.

A buyer who acquired an established Footscray townhouse in August 2026 and plans to acquire a new apartment off-the-plan in Docklands in 2027 will be able to offset any loss from the Footscray property against rental income from the Docklands property from the 2027-28 year onward. But if both properties generate losses, those losses can only be carried forward, not claimed against wage income in the same year. Structuring the loans separately allows the buyer to sell one property without triggering a refinance of the other, which becomes relevant if one asset underperforms and needs to be exited to rebalance cash flow.

Serviceability Buffers and DTI Limits on Investor Loans

Lenders assess your ability to service an investment loan at a rate 3.0 percentage points above the actual loan rate. Rental income is included but is typically shaded by 20 per cent to account for vacancies, which means a property generating $30,000 in annual rent is assessed as contributing $24,000 to serviceability. From February 2026, lenders are also restricted by APRA from lending more than 20 per cent of their total investor loan book to borrowers with a debt-to-income ratio of six times or greater. This applies to your total debt, including investment and owner-occupied loans, measured against your gross income.

If you earn $120,000 and already hold $600,000 in debt, you sit at a DTI of five and have room to borrow further. If you hold $720,000 in debt, you sit at a DTI of six, and any lender extending further credit must count you within their 20 per cent cap. In practice, lenders reserve that cap for their most creditworthy borrowers, which means investors at or near a DTI of six face higher scrutiny, lower rate discounts and more frequent declines even if their income and deposit are sufficient.

Structuring your loans to maximise rental income shading and minimise non-deductible debt improves your serviceability position. That means avoiding redraws for personal use, keeping owner-occupied and investment debts separate, and selecting properties where the rental yield supports the repayment requirement under the serviceability buffer.

LVR, LMI and Portfolio Growth

Most lenders cap investment loans at 90 per cent LVR, with some capping at 80 per cent depending on location, property type and your borrowing history. Borrowing above 80 per cent requires LMI, which is a one-off premium calculated on the loan amount and LVR. The premium is capitalised into the loan and increases your total debt. For a $600,000 loan at 90 per cent LVR, the LMI premium might sit between $15,000 and $25,000 depending on the insurer and your profile.

LMI increases your upfront cost but allows you to enter the market sooner with a smaller deposit. The trade-off is higher debt and higher repayments, which reduces your remaining borrowing capacity for subsequent purchases. In a rising market, paying LMI to secure a property now may be worth more than waiting another two years to save a larger deposit. In a flat or falling market, the extra debt works against you.

Investors building portfolios quickly often accept LMI on the first property to accelerate the timeline, then rely on equity growth in that property to fund deposits for the next purchase without LMI. The structure depends on the sequence. If your first property is a high-growth inner-city apartment, paying LMI to acquire it sooner captures more capital growth over the same period. If your first property is a regional house with modest growth, avoiding LMI by waiting for a larger deposit leaves you with more borrowing capacity later.

Call one of our team or book an appointment at a time that works for you. We'll look at your income, your existing debt, and the properties you're targeting, then map out the structure that keeps your options open as your portfolio grows.

Frequently Asked Questions