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How to Structure an Investment Loan Correctly

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JG
Jason Given
Mortgage broker · MFAA member · Lendology, Adelaide
By Steve Chin · March 2026 · 5 min read

When most investors think about their investment loan, they focus almost entirely on the rate. The structure of the loan often has a far greater long-term impact.

Principal and interest vs interest only

Interest-only loans maximise cash flow and keep deductible interest expenses higher. But they do not suit every strategy. We recommend the right structure for your specific goals - not a one-size-fits-all approach.

Cross-collateralisation - why to avoid it

Cross-collateralisation means using multiple properties as security for a single loan. This can significantly limit your flexibility. We structure investment loans to keep each property's security separate wherever possible.

Offset accounts and investment loans

An offset account reduces the interest payable on an investment loan - but it also reduces the deductible interest expense. We structure your loans to maximise both cash flow and tax efficiency.

Getting it right from the start

It is significantly harder to restructure loans after the fact. Getting the structure right before settlement protects your ability to build a portfolio over time.

Why loan structure matters as much as the interest rate

Most investors focus on getting the lowest rate. The structure of the loan - how it is set up, whether it is interest-only or principal and interest, how it connects to your other lending, and which lender it is with - has a greater impact on your long-term financial outcome than a 0.1% rate difference.

A poorly structured investment loan can contaminate your tax deductions, restrict your ability to access equity for future purchases, and create a cross-collateralisation problem that limits your options for years. Getting it right from day one costs nothing extra and protects you from expensive mistakes.

Interest-only versus principal and interest for investors

Most investment property advisers and accountants recommend interest-only loans for investment properties, at least in the early years. The reason is twofold: cash flow and tax.

Interest-only repayments are lower than principal and interest repayments, which improves your cash flow from the investment. And because interest on an investment loan is tax deductible but principal repayments are not, interest-only maximises your deductible expense. The money you save on principal repayments can be directed to an offset account on your home loan instead - paying down non-deductible debt more efficiently.

The strategy: use interest-only on your investment loan and redirect the cash flow saving into an offset account on your home loan. You reduce non-deductible debt faster while maintaining full deductibility on the investment loan. Discuss this with your accountant before implementing.

Keeping investment loans completely separate

The ATO requires investment loans to be completely separate from personal borrowings for interest to remain fully deductible. Mixing investment and personal funds in the same account - even once - can contaminate the deductibility of the interest on that account permanently.

This means: a dedicated offset account for your investment property (separate from your home loan offset), a separate transaction account for rental income and expenses, and no personal spending from the investment loan account. Lendology sets up the structure correctly from day one so this contamination risk is eliminated.

Cross-collateralisation - when to avoid it

Cross-collateralisation means using one property as security for another property's loan. Banks sometimes encourage this structure because it gives them more security. It creates serious problems for investors as their portfolio grows.

When properties are cross-collateralised, you cannot sell or refinance one without the bank's involvement in the other. Accessing equity requires the bank to revalue both properties. And if one property falls in value, it can affect the LVR position of the other. Lendology structures investment loans as standalone lending wherever possible - each property secured against itself only.

Standalone lending
Each property secures only its own loan. Full flexibility to sell, refinance or access equity independently.
Cross-collateralised
Multiple properties as security for multiple loans. Simpler to set up but restricts future flexibility significantly.
Lender per property
Spreading loans across multiple lenders reduces concentration risk and improves negotiating position on rates.
Equity access
Standalone structure makes equity releases simpler and faster - you deal with one lender for one property.

Frequently asked questions

Should I use a separate loan for each investment property?

Yes, in most cases. Keeping each investment property in its own standalone loan, ideally with its own lender, maximises flexibility and protects each property from issues affecting the others.

Can I claim the full interest on my investment loan as a tax deduction?

Generally yes, provided the loan is used entirely for investment purposes and kept completely separate from personal borrowings. Mixed-use accounts can contaminate deductibility. Confirm your specific situation with your accountant.

How do I access equity in my investment property to buy another one?

You apply to the lender for an equity release - a top-up of the existing loan secured against the investment property. The lender revalues the property and releases up to 80% of the new value minus the existing loan balance. Lendology manages this process.

Is it better to have interest-only or principal and interest on an investment loan?

For most investors, interest-only is more tax-efficient because interest is deductible but principal repayments are not. The right answer depends on your tax position, cash flow and investment strategy. Discuss with your accountant and Lendology before deciding.

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Investment property loans Adelaide Refinancing Adelaide

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