For many Australian homeowners, the most powerful asset they own isn’t sitting in a savings account — it’s locked inside their property. Years of mortgage repayments, combined with rising property values in many markets, have left a significant number of owner-occupiers sitting on substantial equity they haven’t yet put to work.
Refinancing to buy an investment property is one of the most common strategies mortgage brokers see across the country. Done well, it lets you use the value you’ve already built to fund a second purchase without needing to save a full cash deposit from scratch. Done without proper planning, it can saddle you with mismatched loan structures, unexpected tax complications, and cash flow pressure that puts both properties at risk.
This guide explains how the process actually works in Australia — from calculating how much equity you can realistically access, to structuring the refinance so it doesn’t create problems down the track. Whether you’re buying your first investment property or looking to grow a portfolio, the decisions you make at this stage will follow you for years.
If you’d like to explore your own position before reading further, it helps to understand what each part of this process looks like in practice. Whether you’re looking at your options for refinancing your current mortgage, considering an investment loan for a new property purchase, or want to understand how much you could access through a home equity loan, each of these decisions connects back to the same core question: how much equity you have, and whether your income supports the next step.
What “Using Equity” Actually Means
Equity is simply the difference between what your property is worth and what you still owe on it. If your home is valued at $900,000 and your mortgage balance is $500,000, you have $400,000 in equity on paper.
But not all of that equity is usable. Most lenders in Australia will allow you to borrow up to 80% of your property’s value without requiring Lenders Mortgage Insurance (LMI). That 80% threshold is what determines your usable equity — the amount you can actually access for another purpose.
Using the same example: 80% of $900,000 is $720,000. Subtract your existing loan of $500,000 and you’re left with $220,000 in usable equity. That’s what you could potentially release without crossing into LMI territory.
If you’re comfortable paying LMI — or if your lender agrees to waive it under certain conditions — you could access more. But for most investors, staying at or below 80% LVR (loan-to-value ratio) is the cleaner and more cost-effective starting point.
It’s also important to understand that usable equity and borrowing capacity are two separate things. You might have $220,000 in usable equity, but whether the bank will actually lend you that money depends on a separate question entirely: can your income support the repayments on both your existing loan and the new investment debt?
How the Refinancing Process Works in Australia
Refinancing to access equity isn’t complicated, but it does involve more moving parts than a straightforward rate switch. Here’s how the process typically unfolds.
Step 1: Get your property valued
Everything starts with a current valuation. The equity calculation depends on what a lender believes your property is worth today — not what you paid for it or what a neighbour sold for recently. Your broker can often arrange an upfront valuation through the lender before you submit a full application, which helps you know where you stand before committing to anything.
Step 2: Calculate your usable equity
Once you have a confirmed valuation, the calculation is straightforward. Multiply the property value by 0.80, then subtract your outstanding loan balance. The result is your usable equity at an 80% LVR.
Step 3: Assess your borrowing capacity
Now comes the part that catches many borrowers off guard. Even if your equity calculation looks healthy, the lender still needs to be satisfied that your income can service the new debt. Under current APRA guidelines, lenders are required to test your ability to repay at least 3 percentage points above the loan’s actual interest rate. This is the serviceability buffer, and it applies to your total debt — both the refinanced loan and the new investment borrowing.
Lenders will also factor in your living expenses, any existing debts like car loans, personal loans, credit card limits and HECS/HELP balances, as well as how they treat your rental income from the investment property. Most lenders shade rental income — typically applying only 70% to 80% of the projected rent in their calculations — which means the investment property’s income alone won’t fully offset the new borrowing.
Step 4: Choose your loan structure
This is one of the most important decisions you’ll make, and one that competitors rarely explain well. There are several ways to structure the equity release, and each has different implications for tax, flexibility, and record-keeping.
Step 5: Apply, get conditional approval, and settle
Once your structure is agreed, you submit the full application, the lender completes its assessment, and you receive conditional approval. The equity is then either released to you as a separate loan split or made available as a line of credit, depending on what you’ve set up. You use those funds as a deposit and toward purchasing costs on the investment property, then settle both transactions.
Common Loan Structures: What Your Options Actually Are
There’s more than one way to release equity, and the right structure depends on your goals, tax situation, and how you plan to use the funds.
Standalone equity split
This is the structure most brokers prefer for investment purposes. Rather than blending your equity release into your existing home loan, you create a separate loan split secured against your owner-occupied property. The funds from this split are used as the deposit for the investment property, which then carries its own separate loan with its own security.
The advantage is clarity. The equity split has a clear, documented purpose — funding an investment — which makes it straightforward to argue the interest is deductible against the rental income. It also keeps your owner-occupied debt and investment debt clearly separated, which matters for record-keeping and for managing your finances as the portfolio grows.
Cash-out refinance
Some borrowers refinance their entire home loan to a new lender and increase the total amount to release equity in a lump sum. This can be a good option if you’re also chasing a significantly better interest rate, but it comes with refinancing costs — including discharge fees from your current lender, application and settlement fees at the new one, and potentially break costs if you’re on a fixed rate.
Loan top-up
If you’re staying with your existing lender, you may be able to simply increase your home loan to release equity, without going through a full refinance. This is simpler and cheaper, but it can blur the line between private and investment borrowing if the top-up isn’t structured as a separate split.
Line of credit
A line of credit gives you access to equity as needed, up to a set limit, rather than releasing it all at once. This flexibility appeals to some investors — particularly those exploring debt recycling strategies — but the ATO has specific guidance on how interest deductibility applies to line-of-credit facilities, particularly around redraw. If a line of credit is used for both private and investment purposes, working out which interest is deductible becomes complicated and can require apportionment.
Cross-collateralisation: what to know
Some lenders will suggest securing the new investment loan against both properties — your home and the investment — rather than releasing equity separately. This is called cross-collateralisation, and while it can sometimes simplify the initial approval, it creates complications later. If you want to sell one property, refinance, or access equity again, the lender has a charge over both assets and has more control over the process. Most experienced property investors and brokers avoid unnecessary cross-collateralisation for exactly this reason.
How Much Can You Actually Borrow?
It helps to walk through a realistic example. Say you own a home worth $850,000, with $380,000 still owing on the mortgage. Your usable equity at 80% LVR is $300,000 (80% of $850,000 is $680,000, minus $380,000 equals $300,000).
You want to buy an investment property for $650,000. You’ll need roughly $130,000 for a 20% deposit, plus approximately $25,000 to $35,000 for stamp duty and purchasing costs depending on the state — so around $160,000 to $165,000 in total cash required.
You have $300,000 in usable equity, which covers that comfortably. But the lender still needs to assess whether your income can service both your $380,000 owner-occupied loan and the new $520,000 investment loan ($650,000 minus the 20% deposit), including the serviceability buffer.
If your income supports the combined debt, the structure would typically look like this: a $160,000 equity split secured against your home (for the deposit and costs), plus a $520,000 investment loan secured against the new property. Two separate loans. Two separate securities. Clean lines between each purpose.
The Tax and Deductibility Issues Most Articles Skip
Australian tax law on investment borrowing is purposeful and specific. The ATO’s position is that interest deductibility follows the use of the funds, not the security used to obtain them.
That means if you release equity from your home and use it to fund an income-producing investment, the interest on that equity split is potentially deductible — even though it’s secured against your owner-occupied property. Conversely, if you redraw from an investment loan to pay for a holiday or personal expenses, that portion of the interest may not be deductible, regardless of which property secures the debt.
This is why loan structure and record-keeping matter so much. A few common traps worth knowing about:
Mixing private and investment use in the same loan account creates an apportionment headache. If your equity split is later used partly for personal spending, the deductible and non-deductible portions need to be calculated and tracked separately.
Redraw is treated differently from offset. If you make extra repayments into your investment loan and later redraw those funds for a private purpose, the ATO may treat the redrawn amount as a new borrowing for a private purpose — making the interest non-deductible. An offset account linked to an investment loan doesn’t carry the same risk because the offset funds remain separate from the loan balance.
This article is not tax advice, and you should speak with your accountant before finalising any structure. But understanding the basics helps you ask the right questions and avoid structuring decisions that cost you deductions later.
Costs to Budget For
Refinancing to access equity isn’t free, and neither is buying an investment property. Before you commit, it’s worth mapping out what you’ll spend.
On the refinancing side, you may encounter discharge fees from your current lender (often $150 to $400), application or establishment fees at the new lender, legal or settlement fees, and a property valuation fee. If you’re breaking a fixed-rate loan early, break costs can be significant — sometimes thousands of dollars depending on the rate differential and remaining term. Your broker should be able to get an indicative break cost figure from your current lender before you decide.
On the investment property side, your main costs beyond the deposit are stamp duty (which varies by state and property value), conveyancing fees, building and pest inspections, and potentially a buyer’s agent fee if you’re using one. In some states, there are concessions or exemptions for certain types of purchases, but investors generally pay full stamp duty rates.
LMI is another cost to consider if you plan to borrow above 80% LVR on either property. LMI can run into tens of thousands of dollars depending on the loan size and LVR. In some circumstances — particularly when borrowing capacity is strong and the investment opportunity is compelling — paying LMI to access more equity may still make financial sense. But it’s worth modelling the numbers carefully.
When Refinancing May Not Be the Right Move
Not every borrower who has equity should be refinancing to invest. A few situations where waiting or taking a different approach may serve you better:
Your income doesn’t comfortably service both loans at the test rate. Being approved right at the edge of your borrowing capacity leaves no buffer for rate rises, income changes, or unexpected property costs. A vacancy period on the investment, a repair bill, or even a career change can create serious cash flow pressure if there’s no financial headroom.
You’re in the early years of a fixed-rate loan. Break costs can wipe out any short-term benefit from refinancing, particularly if rates haven’t moved significantly since you fixed.
The investment property has weak fundamentals. Equity alone doesn’t make a property a good investment. If the rental yield is poor, the growth prospects are uncertain, or the property needs significant work, the numbers need to stack up on their own merits — not just because you happen to have accessible equity.
Your loan purpose will be mixed. If the equity release will partly fund private spending and partly fund an investment, the tax treatment becomes complicated and the deductibility of interest is compromised. In these situations, separating the purposes clearly — even if that means a smaller, cleaner equity release now — is usually the wiser move.
Real Borrower Scenarios
Sometimes the concepts land better when you can see how they apply in practice. Here are a few situations that come up frequently in broker conversations.
The long-term owner-occupier. A couple in their mid-40s have lived in their Sydney home for 12 years. They’ve paid the mortgage down to $310,000 and the home is now worth $1.1 million. Their usable equity at 80% LVR is $570,000 — more than enough for a strong deposit on an investment property. Their combined income is solid and passes serviceability comfortably. The broker structures a $200,000 equity split against the home to cover the deposit and buying costs on a $750,000 investment property in a regional hub, with a separate $550,000 investment loan secured against the new property. Two clean loan facilities. Clear tax records from day one.
The rentvester. A 34-year-old who has been renting in the city for lifestyle reasons bought an apartment in a growth suburb five years ago as an investment. It’s now worth $680,000, with $410,000 still owing. Usable equity at 80% LVR is $134,000. That’s enough for a deposit on a lower-priced second investment property, but servicing is the constraint — two investment properties plus rent means the income needs to carry a lot of debt. The broker works through the numbers carefully and identifies a purchase price range where the deal stacks up, with a short-term interest-only period on the second investment loan to ease cash flow during the early years.
The accidental landlord. A borrower bought a two-bedroom townhouse as her first home five years ago. She’s moved in with a partner and is now considering renting out her townhouse rather than selling. The property has appreciated well, the mortgage is modest relative to the value, and she’d like to eventually buy a larger home with her partner. Before doing anything, the broker explains how converting the property’s loan purpose from owner-occupied to investment affects her interest deductibility going forward, and discusses whether to retain the loan structure or restructure ahead of the eventual owner-occupied purchase.
The self-employed borrower. A business owner with strong cash flow but income that fluctuates year-to-year has $350,000 in usable equity. The challenge isn’t the equity — it’s demonstrating income to the lender’s standard. Some lenders will accept one year of tax returns for self-employed borrowers in certain circumstances; others require two. The broker identifies lenders whose policy suits the borrower’s income documentation and structures the application accordingly, avoiding a blunt approach that would result in a straight decline.
Frequently Asked Questions
Can I refinance my home loan to buy an investment property?
Yes, this is a well-established strategy in Australia. You release equity from your existing property — typically up to 80% of its value minus what you owe — and use those funds as a deposit and toward purchasing costs on the investment property. The investment property then carries its own separate loan.
How much equity do I need to buy an investment property?
A useful starting point is to calculate 20% of the investment property’s purchase price plus estimated stamp duty and purchasing costs — typically another 3% to 5% depending on the state and purchase price. That gives you the total equity you’ll need to release. You also need to confirm that your income supports the combined debt load at the lender’s serviceability test rate.
What’s the difference between usable equity and borrowing capacity?
Usable equity is the dollar amount you can access from your existing property based on its current value and what you owe. Borrowing capacity is whether your income — after accounting for all existing and proposed debts, living expenses, and the serviceability buffer — is sufficient to service the new loan. Both need to work. You can have significant equity and still be declined if your income doesn’t support the new debt.
Will I have to pay LMI when I refinance?
Not necessarily. If the total amount you’re borrowing against your existing property stays at or below 80% of its value, LMI generally won’t apply to that loan. On the investment property itself, LMI also won’t apply if you’re borrowing 80% or less of the purchase price — which is why using the equity release as a 20% deposit is a common and clean approach.
Is it better to cross-collateralise or use a separate equity split?
Most experienced investors and brokers prefer separate securities. Cross-collateralisation gives the lender more control over both properties, which can complicate future refinancing, equity access, or selling decisions. A standalone equity split against your existing property — used to fund the deposit — keeps the properties independent of each other and is generally easier to manage over time.
Is the interest on my equity split tax deductible?
If the equity split funds are used for an income-producing purpose — such as a deposit on a rental property — the interest on that split is potentially deductible, even though it’s secured against your owner-occupied home. Deductibility follows the purpose of the funds, not the security. Speak with your accountant to confirm how this applies in your specific situation and to ensure your loan structure supports a clean deductibility position.
Can I use an offset account to reduce interest while keeping my equity structure clean?
Yes, an offset account linked to your equity split can reduce the interest payable on that loan without affecting its deductibility — as long as the offset funds themselves are clearly not coming from a mixed source. This is one reason brokers often prefer offset accounts over redraw facilities for investment loans: offset keeps the funds separate from the loan balance, while redraw can create issues if the funds are later used for private purposes.
How long does refinancing to release equity usually take?
A straightforward refinance through a broker typically takes three to six weeks from application to settlement, though timelines vary depending on the lender’s turnaround, the valuation process, and whether any additional documentation is required. If you’re also purchasing an investment property simultaneously, coordinating both settlements adds some complexity — your broker can help manage the timing.
Should I use interest-only on my investment loan?
Interest-only can reduce your monthly cash outgoings in the early years of an investment, which some investors use to preserve cash flow and redirect surplus income toward non-deductible owner-occupied debt. However, interest-only periods are limited — lenders typically allow up to five years at a time — and you need to be confident the investment will grow enough in value and rental income to justify the structure. It’s not appropriate for everyone and should be considered alongside your broader financial position.
What happens if I want to turn my current home into an investment property later?
This is a situation where planning ahead matters. The moment a property’s use changes from owner-occupied to investment, the interest on the loan starts to become deductible. However, if you’ve made extra repayments and then redraw from that loan for private purposes later, those redrawn funds are treated as a new non-deductible borrowing. The structure of your loan going into that transition can significantly affect your tax position. An accountant and broker working together can help you set up the loan correctly before the change in use occurs.
The Takeaway
Refinancing to buy an investment property is a legitimate and widely used strategy in Australia — but it rewards those who plan the structure carefully and penalises those who treat it as a simple transaction.
The core of getting it right comes down to three things: understanding how much equity you can actually access, making sure your income genuinely supports both loans under realistic conditions, and structuring the refinance so that your tax position is clean and your loans are easy to manage as the portfolio grows.
Working with a mortgage broker who understands investment lending — not just rate comparisons — is worth the effort at this stage. The structuring decisions made when you release equity for the first time tend to either set you up well for future purchases or create complications you spend years untangling. Get the structure right from the start, and each subsequent step in building a portfolio becomes more straightforward.