Fixed rate investment loans lock in your interest rate for a set period, which protects you from rate increases but removes access to an offset account on the fixed portion.
Most investors assume an offset account works the same way across any loan structure. It doesn't. When you fix the rate on an investment loan, the offset feature stops reducing interest on that fixed portion. The offset only works on variable rate balances, which means your loan structure directly affects how much tax-deductible interest you actually pay.
Fixed Rate Investment Loans Don't Allow Offsets on the Fixed Portion
When you fix the rate on an investment loan, lenders calculate interest using the fixed rate for that entire portion of the loan, regardless of any cash sitting in an offset account. The offset account can only reduce interest charged on the variable portion of your loan. If your entire loan is fixed, the offset has no effect on interest charges during the fixed period.
Consider an investor who borrows $500,000 to purchase a rental property and fixes the entire loan at 5.8% for three years. They maintain $50,000 in an offset account expecting it to reduce their interest bill. During the fixed term, that $50,000 sits idle. The loan still accrues interest on the full $500,000 at the fixed rate. Once the fixed term ends and the loan reverts to variable, the offset starts working again, but until then, the investor pays interest on funds they already have.
This becomes particularly relevant for investors using negative gearing. You want to maximise tax-deductible interest on your investment loan while keeping non-deductible debt, like your home loan, as low as possible. Parking cash in an offset that isn't reducing investment loan interest means you're not optimising your deductions.
Split Loans Let You Use Both Fixed Rates and Offsets
A split loan divides your borrowing into separate portions, typically one fixed and one variable. The fixed portion locks in a rate, while the variable portion remains flexible and compatible with an offset account. This structure lets you manage rate risk while still benefiting from offset functionality on part of your loan.
The usual approach is to fix a percentage of the loan, commonly 50% to 70%, and leave the rest variable with an offset attached. If you borrow $400,000 for an investment loan, you might fix $280,000 at a set rate and keep $120,000 variable with a linked offset account. Any cash in the offset reduces interest on that $120,000 variable portion. The fixed portion remains unaffected by the offset, but you still gain rate certainty on the majority of the loan.
You can adjust the split percentage based on how much cash you expect to hold and how strongly you want protection from rate rises. Investors with irregular income or large cash reserves often keep a higher variable portion to make full use of the offset. Those prioritising certainty over flexibility might fix a larger percentage.
Some lenders allow multiple splits, which means you could fix portions at different rates or terms and still maintain a variable component with an offset. This adds complexity but also gives you more control over how your loan behaves as rates change.
Why Offset Accounts Still Matter for Investment Loans
Even when part of your loan is fixed, the offset account plays an important role in managing your overall tax position and cash flow. The variable portion of a split loan still benefits fully from any funds held in the offset, which reduces the interest you pay and the interest you can claim as a deduction.
Investors often use offset accounts to hold rental income, savings, or business funds. Keeping this cash in an offset linked to the variable portion of your investment loan reduces non-deductible interest on your home loan if you structure your debts correctly. The key is making sure the offset is attached to the loan where it delivers the most value.
If you're using a debt consolidation strategy or drawing on equity release from another property, the way you structure offsets across multiple loans affects both your tax position and your repayment flexibility. Investors with more than one property need to think about which loan gets the offset and how that aligns with their broader borrowing strategy.
Some lenders charge a monthly fee for offset accounts, typically between $10 and $20. On an investment loan, this fee is a tax-deductible expense, but it still reduces the net benefit of the offset if you're not holding enough cash in the account to outweigh the cost.
Fixed Rate Break Costs Can Outweigh Offset Savings
If you decide to refinance, sell the property, or pay down the fixed portion of your loan early, the lender may charge a break cost. This fee compensates the lender for the difference between the rate you locked in and the current market rate. Break costs can run into thousands of dollars, particularly if rates have fallen since you fixed.
Investors sometimes assume they can refinance to access a lower rate or better offset features without penalty. If your loan includes a fixed portion, refinancing during the fixed term almost always triggers break costs. Even switching from a fixed rate to a variable rate with the same lender can incur this charge.
The variable portion of a split loan doesn't attract break costs, so you maintain flexibility on that part of the borrowing. You can make extra repayments, refinance, or pay it off entirely without penalty, while the fixed portion remains locked in.
Before committing to a fixed rate on an investment loan, consider how long you plan to hold the property and whether you're likely to need flexibility before the fixed term ends. If there's a reasonable chance you'll sell, restructure, or access equity release within the fixed period, a smaller fixed portion or a shorter fixed term reduces your exposure to break costs.
How Lenders Treat Offsets on Investment Loan Applications
When you apply for an investment loan, lenders assess your borrowing capacity based on the loan's interest rate and repayment type. If you're applying for interest-only repayments on the investment loan, which is common for investors maximising cash flow, the lender calculates serviceability using the interest-only rate and term.
The presence of an offset account doesn't change how the lender assesses your capacity to service the loan. They calculate repayments based on the full loan amount, not the net position after accounting for any offset balance. This means you can't rely on offset funds to improve your borrowing capacity on paper, even though they reduce your actual interest cost.
If you're structuring a split loan with both fixed and variable portions, some lenders apply different interest rates to each portion, which can affect the overall cost and your ability to compare products. A lender offering a lower fixed rate might charge a higher variable rate, which reduces the benefit of the offset on the variable portion.
Most investment loan products allow you to link one offset account per loan split, but not all lenders offer offsets on variable investment loans. Some budget lenders and smaller institutions don't provide offset accounts at all, even on variable products. If offset functionality matters to your strategy, confirm the lender supports it before proceeding with an application.
Interest-Only Loans and Offset Accounts
Most investors choose interest-only repayments for the first few years of an investment loan to improve cash flow and maximise tax deductions. When you combine interest-only repayments with a variable rate and an offset account, the offset reduces the interest portion of your repayment without requiring you to pay down the principal.
If you're holding $30,000 in an offset linked to a $350,000 variable investment loan on interest-only terms, you only pay interest on $320,000. The principal remains at $350,000, which means your loan balance stays the same and your tax-deductible interest is calculated on the net amount. This approach keeps your investment debt high, which suits investors focused on leveraging equity and building a portfolio rather than paying down individual loans.
Once the interest-only period ends, the loan typically reverts to principal and interest repayments. The offset still functions the same way, reducing interest on the net balance, but your minimum repayment increases because you're now required to pay down the principal as well. Planning for this transition matters, especially if you're relying on rental income to cover repayments.
Investors using interest-only terms on a split loan structure need to confirm whether both the fixed and variable portions are interest-only, or just one. Some lenders allow interest-only on the variable portion but require principal and interest on the fixed portion, which changes your cash flow and repayment profile.
Call one of our team or book an appointment at a time that works for you. We'll help you structure your investment loan to balance rate certainty with offset flexibility, and make sure your borrowing aligns with your tax position and long-term property strategy.
Frequently Asked Questions
Do offset accounts work on fixed rate investment loans?
No, offset accounts do not reduce interest on the fixed portion of an investment loan. The offset only works on variable rate balances, so if your entire loan is fixed, the offset has no effect during the fixed term.
What is a split loan and how does it help investors?
A split loan divides your borrowing into fixed and variable portions. The fixed portion locks in a rate for certainty, while the variable portion remains flexible and compatible with an offset account, letting you benefit from both rate protection and offset functionality.
Can I refinance a fixed rate investment loan without penalty?
Refinancing during the fixed term usually triggers break costs, which can be significant if rates have fallen since you locked in. The variable portion of a split loan can be refinanced without penalty, but the fixed portion remains locked in.
How do offset accounts affect my tax deductions on an investment loan?
An offset reduces the interest you pay, which also reduces the interest you can claim as a tax deduction. However, it can improve your overall tax position if used strategically to reduce non-deductible debt like a home loan.
Do all lenders offer offset accounts on investment loans?
No, not all lenders provide offset accounts on investment loans. Some budget lenders and smaller institutions don't offer offsets even on variable products, so it's important to confirm this feature is available before applying.
