Avoid These 5 Mistakes When Refinancing Your Investment Property

Refinancing an investment property loan isn't just about chasing a lower interest rate.

Unlike your home loan, every dollar you pay in interest on an investment property is typically tax-deductible, which means the rate you see isn't the rate you truly pay. The structure you choose affects your cashflow, your ability to access equity for future purchases, and how the ATO treats your deductions. Getting it right means understanding what actually matters when you hold property for income and growth.

Mistake 1: Ignoring the After-Tax Rate When Comparing Loans

The headline interest rate matters less for an investment loan because you claim the interest as a deduction. If you're on a marginal tax rate of 37%, a 6% interest rate costs you closer to 3.78% after tax. A loan with slightly better features at 6.10% might still make more sense than a bare-bones loan at 5.90% if it gives you offset accounts or partial interest-only options that improve your cashflow or flexibility.

We regularly see investors in Parramatta refinance to the lowest advertised rate without considering how they'll use the loan over the next few years. If you're planning to buy another property soon, you need access to equity and loan structures that don't penalise you for drawing down again. A loan that looks cheaper now but costs you $3,000 in discharge fees and valuation costs when you refinance again in 18 months isn't saving you money.

Mistake 2: Switching from Interest-Only to Principal and Interest Without Running the Numbers

Many lenders push investors toward principal and interest repayments during a refinance, especially if your original interest-only period has ended. Paying down the principal sounds sensible, but it reduces your tax-deductible debt and ties up cash you might need for maintenance, another deposit, or personal expenses.

Consider an investor who owns a unit near Parramatta Square with a loan of $550,000. Switching from interest-only to principal and interest increases their monthly repayment by around $1,400. That's $16,800 a year in cashflow they no longer have available. If they're holding the property long-term and don't need that cash, it might suit them. But if they want to buy another investment property within a few years, they've just made it harder to save a deposit and demonstrate serviceability to a lender.

If your fixed rate period is ending and you're being moved to principal and interest automatically, it's worth reviewing whether that suits your investment strategy. You can read more about what happens when your fixed rate expires and the options available during that transition.

How Lenders Assess Investment Loan Refinancing Differently

Lenders assess investment loans by looking at rental income, but most will only count 80% of the rent you receive when calculating serviceability. They also apply a higher interest rate buffer than they do for owner-occupied loans, usually adding 3% to the current rate to stress-test whether you can afford repayments if rates rise.

This means refinancing an investment loan is harder to approve than refinancing your home, even if the loan balance is similar. If your income has changed, you've taken on other debt, or rental yields in your area have softened, you might not qualify for the same loan amount you currently have. Running a loan health check before you apply lets you know where you stand and whether you need to adjust your strategy before approaching a lender.

Mistake 3: Refinancing Without a Plan to Access Equity

One of the most common reasons investors refinance is to access equity for their next purchase. But many don't structure the refinance correctly, which means they end up paying for two valuations, two sets of application fees, and two rounds of paperwork within a short period.

If you're refinancing now and planning to buy again in the next 12 to 24 months, the structure you choose matters. You want a lender that will allow you to increase your loan limit without a full refinance, and you want your loan-to-value ratio assessed in a way that leaves room for future borrowing. Some lenders will let you pre-approve an equity release at the time of refinancing, so when you're ready to buy, you just request a drawdown rather than start from scratch.

In Parramatta, where property values have shifted over the last few years, getting a current valuation as part of your refinance can reveal whether you have more equity available than you realised. If your property has increased in value and your loan balance has reduced, you might be sitting on $100,000 or more in usable equity without knowing it. That equity can fund your next deposit, but only if your loan structure allows you to access it without refinancing again.

Mistake 4: Consolidating Investment and Personal Debt into One Loan

It's tempting to roll your car loan, personal loan, or credit card debt into your investment mortgage when you refinance. The interest rate will be lower, and your repayments will drop. But doing this turns non-deductible debt into a mix that includes your deductible investment loan, and the ATO doesn't let you claim interest on the portion used for personal purposes.

If you borrow an extra $30,000 during your refinance to pay off a car loan, that $30,000 becomes part of your mortgage balance, but the interest on it isn't deductible. Your accountant will need to split your loan for tax purposes, which adds complexity every year and increases the risk of errors. Keeping your investment loan separate from personal borrowing makes your tax return cleaner and protects your deductions.

Mistake 5: Assuming Your Current Lender Will Offer You the Same Deal as a New Customer

Lenders spend heavily to attract new customers, but they rarely extend the same rates or incentives to existing borrowers. If your fixed rate period is ending or you're on a variable rate that hasn't moved in line with recent cuts, your current lender is unlikely to offer you their sharpest pricing unless you're prepared to walk.

Calling your lender and asking for a rate reduction sometimes works, but it's more common to get a token discount that still leaves you paying more than a new customer would. Refinancing to a different lender often delivers a lower rate, better loan features, and cashback or fee waivers that your current lender won't match. The application process takes a few weeks, but the saving over the life of the loan can reach tens of thousands of dollars depending on your balance and the rate difference.

For investors in Parramatta managing multiple properties, a refinance is also an opportunity to consolidate loans with one lender if that improves your serviceability, or to split them across lenders if you want to protect your options. There's no one-size-fits-all approach, but staying with your current lender by default usually isn't the most cost-effective choice.

Refinancing an investment property is about more than rate. It's about cashflow, tax treatment, equity access, and how the loan fits your broader property strategy. If you're coming off a fixed rate, planning your next purchase, or just want to confirm you're not paying more than you should, a structured review of your current loan will show you what's possible.

Call one of our team or book an appointment at a time that works for you. We'll run the numbers, compare your options, and make sure your loan structure supports what you're actually trying to achieve.

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