Refinancing an investment property is one of those moves that sounds obviously good until you run the numbers. Lower rate, lower repayments, maybe some equity freed up for the next purchase. Simple.
Except it rarely is. The decision to refinance sits at the intersection of loan structure, tax rules, and portfolio timing. Get those wrong and you trade a short-term rate cut for tens of thousands in extra interest over the life of the loan.
Here is the test that matters: Is the rate gap real? Is your equity above 20%? Will the loan purpose stay clean for deductibility? And are you genuinely funding something productive with the proceeds? If all four answers are yes, refinancing works. If any answer is no, pause.
What refinancing an investment property actually means
You replace your existing investment loan with a new one. The goal is better terms: a lower rate, a different structure, or access to equity that has built up since you bought.
The process mirrors owner-occupier refinancing, but the terms are worse. Investment loans carry higher interest rates and stricter criteria because lenders treat them as higher risk. Serviceability assessments are tighter. And a key difference that catches investors off guard: the ATO's purpose test governs what stays deductible and what doesn't. More on that below.
Four situations where refinancing genuinely pays off
Not every rate drop justifies the paperwork. These four scenarios are the ones where the numbers tend to hold up.
1. The rate gap between lenders is real and material
Variable home loan rates across the market can differ by more than 2%. That is not a rounding error. On a $500,000 loan, a 2% difference changes your annual interest bill by $10,000.
Before you start a formal application, though, tell your current lender you are planning to switch. To keep your business, they may match the competitor rate. If you have at least 20% equity, you have more bargaining power. This single conversation can deliver the same outcome without discharge fees, new applications, or weeks of settlement delay.
2. Your equity has grown past the 20% threshold
Lenders typically require at least 20% equity (80% LVR) to refinance without paying LMI. If your property has appreciated or you have paid down principal, that equity becomes usable.
The right time to refinance is generally when equity has grown enough to take the next step in your investment strategy. That might mean funding a deposit for your next property or covering renovation costs that lift rental income. If you are working toward your first or second investment purchase, our guide on investment property deposits covers how much equity or cash you actually need.
3. You are accessing equity to fund another investment purchase
This is the portfolio-building use case. You draw equity from Property A to fund the deposit on Property B. The interest on the drawn equity stays deductible as long as the funds go toward an investment purpose.
But the numbers need scrutiny. If a cash-out refinance increases your loan from $500,000 to $600,000 at a rate just 0.5% higher than your current one, that adds roughly $139,000 in interest over a 25-year term and reduces your future borrowing capacity by around $150,000. The equity you unlock must generate returns that outweigh both costs.
If you are weighing up your next purchase, our guide to buying investment property in Australia covers the full acquisition process.
4. Your fixed rate is expiring anyway
If your fixed period is ending and you are about to roll onto the lender's standard variable rate, you are effectively being forced to make a decision. Comparing the market at this point costs nothing extra because there are no break fees to worry about.
If you are mid-fixed-term, the calculation is different. Fixed-rate break costs can eliminate any savings from switching to a lower rate. Get a written break cost estimate from your lender before doing anything else.
The traps: when refinancing costs more than it saves
Resetting the loan term
This is the most common and least discussed mistake. Say you have a $500,000 mortgage and you are five years into a 25-year principal and interest loan. Rates have dropped 0.5%, so refinancing looks attractive. But if you refinance onto a new 25-year term instead of matching your remaining 20 years, it costs you an additional $51,420 in interest. The lower rate gets swallowed by five extra years of compounding.
Always ask the new lender to match the remaining term of your current loan.
Cash-out without a plan
Drawing equity for vague purposes — a renovation you have not scoped, a “buffer,” lifestyle spending — is where refinancing goes wrong. The numbers from the cash-out scenario above bear repeating: topping up $100,000 at a marginally higher rate costs $139,000 in extra interest and cuts borrowing capacity by $150,000. Every dollar drawn needs a job.
LVR sitting above 80%
Some lenders will not even consider a refinance application if your LVR is above 80%. Others will proceed but charge LMI, which can run into thousands and wipe out any rate savings. Check your current LVR before you start comparing offers.
The loan purpose test: what stays deductible
The ATO does not care what your loan was originally for. It cares what the borrowed funds are used for right now. This is the purpose test, and it governs everything about deductibility when you refinance.
If you refinance a $500,000 investment loan and draw an extra $50,000 for a personal car purchase, only the interest on the original $500,000 remains deductible. The $50,000 used personally? That interest is gone from your tax return.
Mixed-use draws must be split proportionally. If you access $100,000 of equity and use $70,000 for another investment property and $30,000 for personal spending, only the interest on the $70,000 investment portion is deductible.
The practical takeaway: keep loan accounts separate. Document exactly where equity proceeds go. Mixed-purpose loans create accounting headaches that compound every year at tax time.
One thing that does not change: refinancing itself does not trigger CGT. That only applies when you sell. And depreciation claims continue unchanged after refinancing as long as the property remains an investment.
What you can and cannot claim
Deductible borrowing expenses
The ATO allows deductions for loan establishment fees, lender's mortgage insurance, title search fees, mortgage document preparation costs, broker fees, lender valuation fees, and stamp duty on the mortgage.
If total borrowing expenses exceed $100, you claim them over the loan term or five years, whichever is shorter. Below $100, claim the full amount in the year you incur them.
Non-deductible costs that still reduce CGT
Stamp duty on the property transfer itself cannot be claimed as a borrowing expense. But it forms part of your cost base for CGT purposes, along with other capital costs like legal fees, conveyancing, inspections, and property valuation fees. These reduce your taxable gain when you eventually sell.
If you have held the property for more than 12 months, you may also be eligible for a 50% CGT discount on the taxable gain.
Similarly, renovation costs funded through refinancing are not immediately deductible but are added to the cost base, reducing CGT on sale. Keep every receipt.
The 2026 negative gearing changes and refinancing
The 2026-27 Federal Budget introduced a significant shift. Established residential properties purchased after 12 May 2026 cannot be negatively geared from 1 July 2027 onwards. Properties purchased before that date are unaffected.
This matters for refinancing because of what happens when you draw equity to buy your next property. The deductibility of interest on that new borrowing depends on what the funds are used for, not on the original property. If the equity funds a purchase of an established property after 12 May 2026, the negative gearing limitations apply to that new acquisition from 1 July 2027.
Investors refinancing now to build a war chest for future purchases need to factor this into their numbers. The tax benefit that historically made leveraged property acquisition work may not apply to the next deal.
Before you refinance: a practical checklist
Ask your lender to match first. A phone call costs nothing. With 20%+ equity, you have leverage to negotiate. Many investors skip this step and pay thousands in switching costs for a rate their current lender would have matched.
Check your LVR. If it is above 80%, expect LMI charges or outright rejection from some lenders. Get a current valuation before you commit to an application.
Calculate the real break-even. Do not compare interest rates alone. Factor in discharge fees, application fees, valuation costs, and any LMI. A rate difference of 2%+ in the market is worth pursuing, but a 0.2% gap rarely survives the fees.
Keep loan purpose clean. If you are drawing equity, document what the proceeds fund. Separate accounts for investment and personal use. The ATO's purpose test is strict, and mixed-purpose loans create ongoing deductibility problems.
If on a fixed rate, get a break cost estimate. Break costs can wipe out any savings. Get the number in writing before proceeding.
Match the remaining term. Do not default to a new 25 or 30-year loan. Refinancing onto a fresh term is how a rate cut turns into $51,420 in extra interest.
Refinancing an investment property is a portfolio decision, not a rate-shopping exercise. The investors who get it right treat it as a calculated move within a broader strategy. The ones who get it wrong chase a lower monthly repayment and pay for it over decades.
If you are weighing up whether refinancing fits your next move, a strategy session can help you run the numbers against your specific portfolio.