Skip to main content

True wellbeing begins at home.

Refinancing

Refinancing an Investment Property: Get the Structure Right

Published

Refinancing an investment property is not just about the rate. Get the loan structure wrong and you could lose thousands in tax deductions. Here is how to do it properly.

HomeBlogRefinancing an Investment Property: Get the Structure Right

By Jason Given · 2026-08-16 · 7 min read

Why investment property refinancing is different

With an owner-occupied refinance, you are mostly focused on two things: the interest rate and the loan features. Lower rate, better offset, maybe a redraw facility. The structure is straightforward because there are no tax implications to worry about.

With an investment property, the loan structure directly affects your tax position - potentially for years. The interest you pay on an investment loan is tax deductible, but only if the loan is set up correctly. Get the structure right and you save on rate AND maximise your deductions. Get it wrong and the ATO may disallow deductions you were claiming.

This is not hypothetical. We regularly see investors who have refinanced through a bank or online lender and unknowingly contaminated their loan structure. The bank got them a slightly better rate, but nobody thought about the tax side. By the time their accountant spots the problem, it has been costing them for years.

This is where using a broker who understands investment lending pays for itself. The rate matters, but the structure matters more.

The golden rule: purpose determines deductibility

The ATO does not care which property secures the loan. They care what the borrowed funds were used for. This is the single most important concept in investment lending, and the one that trips people up most often.

A loan used to buy an investment property? The interest is deductible. That same loan topped up with $50,000 for a new car? The car portion is NOT deductible. You now have a mixed-purpose loan, and you need to apportion the interest between the deductible investment portion and the non-deductible personal portion.

If you mix purposes in one loan account, you need to track and apportion the interest for every single repayment. This is complex, error-prone, and the kind of thing that makes your accountant charge you more at tax time.

The solution is simple: always use separate loan accounts for different purposes. One account for the investment borrowing. A separate account for anything personal. Clean, clear, and easy to claim.

How to structure a refinance correctly

Whether you are refinancing to a new lender or restructuring with your current one, these are the principles that protect your tax position:

  • 1.Keep the investment loan separate. Do not combine it with your home loan, even if the same lender offers both. The moment you merge investment and personal borrowing into one account, you create a mixed-purpose loan that requires interest apportionment.
  • 2.If releasing equity from your home for an investment deposit, set up a new split/sub-account for the equity release. This keeps deductible and non-deductible interest cleanly separated. Your original home loan stays as-is (non-deductible), and the equity release portion sits in its own account (deductible, because the funds are used for investment).
  • 3.If drawing additional funds at refinance, split them by purpose. Renovation funds for the investment property go in the deductible account. Personal funds go in a separate non-deductible account. Never mix them.
  • 4.Keep records of what every dollar was used for. The ATO can audit years later. Bank statements, settlement statements, invoices for renovations - keep everything. If you cannot prove what the funds were used for, you cannot claim the deduction.
  • 5.Use an offset account on your owner-occupied loan, not the investment loan. Parking cash in an investment loan offset reduces the interest you pay on that loan - which sounds good, but it also reduces your deductible interest. You are better off using the offset on your home loan, where the interest is not deductible anyway.

Common mistakes that cost investors money

These are the errors we see most often - and every one of them is avoidable with the right structure upfront:

  • Combining investment and personal borrowing in one account. This creates a mixed-purpose mess. You will need to apportion every interest payment between deductible and non-deductible, and if you get it wrong the ATO can deny the entire deduction.
  • Parking personal savings in the investment loan offset. This reduces your deductible interest. Every dollar sitting in that offset is costing you a tax deduction. Move it to the home loan offset instead.
  • Refinancing to a new lender without maintaining the split structure. Some lenders combine everything into one account by default. If your previous structure had clean splits, make sure the new lender replicates them.
  • Drawing equity from the investment property for personal use without splitting. This contaminates the deductible loan. Even if the security is the investment property, personal-use funds are not deductible.
  • Not getting accounting advice before restructuring. A 30-minute conversation with your accountant before you refinance can save thousands in lost deductions over the life of the loan. We always recommend our investor clients check with their accountant before finalising a restructure.

The equity release strategy

This is one of the most common scenarios we help investors with, so let's walk through it with real numbers:

You own your home, valued at $800,000 with a $300,000 mortgage. You want to buy a $600,000 investment property with a 20% deposit ($120,000). You do not have $120,000 in cash, but you have plenty of equity in your home.

The solution: refinance your home loan and release $120,000 as a separate split. Here is how the structure looks:

  • Your home loan: $300,000 (interest NOT deductible - it is your home)
  • Equity release split: $120,000 (interest IS deductible - funds used for investment)
  • Investment property loan: $480,000 (interest IS deductible)
  • Total deductible interest: on $600,000 of borrowing

The critical detail is the separate split for the equity release. If you just increased your home loan from $300,000 to $420,000 without splitting it, you would have a mixed-purpose loan. The interest on the extra $120,000 would still be deductible in theory, but proving it and apportioning the interest correctly becomes unnecessarily complicated.

Lendology structures this as standard practice for every investor client. It takes no extra time, costs nothing extra, and protects your tax position from day one.

Refinancing an investment property?
Book a chat with Jason or Steve. We structure the loan to protect your tax deductions and find the best rate across 60+ lenders.
Book a chat

Frequently asked questions

Is interest on an investment property loan tax deductible?

Yes. Interest on a loan used to purchase or improve an income-producing property is tax deductible. The key word is 'purpose' - the deductibility is tied to what the borrowed funds were used for, not the security. If you refinance and draw extra funds for personal use, only the investment portion remains deductible.

What happens to my tax deductions when I refinance?

If you refinance for the same amount as your existing investment loan, the deductibility continues unchanged. If you draw additional funds, the tax treatment depends on what the extra funds are used for. Extra funds used for the investment property (renovations, repairs) remain deductible. Extra funds used for personal purposes (holiday, car) are not deductible.

What is a split loan and why does it matter for investors?

A split loan separates your borrowing into two or more accounts - typically one for the investment purpose (deductible) and one for personal use (not deductible). This clean separation makes tracking deductible interest straightforward and protects your tax position. Without a split, mixed-purpose loans create complicated interest apportionment.

Can I refinance my home loan to buy an investment property?

Yes. You can refinance your owner-occupied home to release equity for an investment property deposit. The key is to structure the equity release as a separate loan account. The interest on the equity release portion is tax deductible (because the funds are used for investment purposes), while the original home loan interest remains non-deductible.

Investing or refinancing?

Book a chat. We structure investment loans to maximise deductions and minimise rate.

Book a chat 08 8270 5138
Related reading
Investment loansRefinancingNegative gearing explainedInvestment loan structure