Beginner's Guide to Fixed Rate Investment Loans

Fixed rate investment loans lock your interest cost for a set period, typically one to five years, which removes rate risk but introduces structural constraints that affect how much you can borrow and how you service the loan over time.

The debt-to-income limit that came into force in February applies separately to investor and owner-occupier lending, and every lender still tests your serviceability at a rate three percentage points above the actual loan rate. When you fix, the test rate compounds quickly. At a fixed investor rate around 5.8 per cent, the serviceability assessment runs at 8.8 per cent or higher. That margin narrows borrowing capacity compared to a variable rate scenario where the starting point might sit lower, even though the buffer remains identical.

Fixed Rate Structures and Serviceability Testing

Lenders calculate your maximum loan amount by stressing your income against all committed expenses, including the new investment loan repayment calculated at the test rate. A fixed rate investment loan with a five-year term at 5.8 per cent is tested at approximately 8.8 per cent. On a loan amount of $600,000, the principal-and-interest repayment at the test rate would be close to $4,400 per month. If you structure the same loan as interest-only during the fixed period, the test rate payment drops to around $4,400 per month on interest alone, but the lender still applies the higher of the two calculations depending on their credit policy.

Rental income from the investment property is included in the serviceability calculation, but it is shaded. Most lenders apply a haircut of 20 per cent to account for vacancy, which means an expected rent of $650 per week contributes $520 per week to your servicing position. Brisbane's inner-city unit market has seen vacancy rates tighten over the past 18 months, but lenders do not adjust the shading based on local conditions. The 20 per cent reduction is a blanket credit policy setting.

Consider an investor buying a two-bedroom unit in Woolloongabba at the current median, with rental income of $650 per week and a household income of $140,000. The shaded rental income adds roughly $27,000 annually to serviceability. After accounting for existing commitments, including a $480,000 owner-occupied loan and typical living expenses, the maximum loan amount on a fixed rate product with interest-only repayments during the fixed term might land around $580,000. Switching to principal-and-interest repayments during the fixed period could reduce that figure by $40,000 to $60,000, depending on the lender's calculation method.

Interest-Only Periods and Portfolio Cash Flow

Interest-only repayments during a fixed term preserve cash flow and allow you to direct surplus income toward other investments or offset accounts linked to your owner-occupied debt. An interest-only period of five years on a $600,000 investment loan at 5.8 per cent fixed costs roughly $2,900 per month. The same loan on principal-and-interest repayments over 30 years would cost close to $3,500 per month. The $600 monthly difference compounds over five years to around $36,000 in retained cash flow, which can be redeployed or held as a liquidity buffer.

Once the interest-only period expires, the loan reverts to principal-and-interest repayments over the remaining term. A $600,000 loan with five years of interest-only payments and 25 years of principal-and-interest repayments will carry a higher monthly cost in the second phase than a loan that was principal-and-interest from the outset, because the principal is being repaid over a shorter period. The monthly repayment in year six, assuming rates remain steady, would rise to approximately $3,800 per month. You need to model that step-up before you commit to the structure.

Interest-only is not universally available on fixed rate investment loans. Some lenders cap the interest-only period at three years even when the fixed rate term is five years. Others restrict interest-only approvals to borrowers with an LVR below 80 per cent or require a minimum income threshold. If you are refinancing an existing investment property and your current LVR sits above 80 per cent due to a valuation decline or because you extracted equity previously, access to interest-only on a new fixed rate may be limited unless you reduce the loan amount or accept a higher rate.

Break Costs and Portfolio Flexibility

A fixed rate investment loan carries an economic cost if you repay the loan or refinance before the fixed term ends. The cost is calculated based on the difference between the fixed rate you locked in and the wholesale rate the lender can achieve by reinvesting the capital for the remaining fixed period. If you fixed at 5.8 per cent for five years and wholesale rates have fallen to 4.5 per cent two years later, the lender loses income over the remaining three years. You are billed for that loss.

Break costs are not capped and are not disclosed upfront because they depend on future rate movements. In a falling rate environment, they can exceed tens of thousands of dollars. In a rising rate environment, the cost may be zero or the lender may even apply a break gain in your favour, though this is rare and policy-dependent. The lack of certainty makes fixed rate loans unsuitable for investors who plan to sell within the fixed term or who intend to access equity for further purchases before the term expires.

If you are building a portfolio and expect to refinance or restructure within two to three years, a shorter fixed term or a split structure offers more control. A common approach is to fix 50 per cent to 70 per cent of the loan amount for two or three years and leave the remainder on a variable rate with an offset account and no restrictions on additional repayments or refinancing. The variable portion can be refinanced or discharged without triggering break costs on the fixed portion, provided the fixed portion remains with the same lender and is not materially altered. This structure is covered in more detail on the investment loans page.

Fixed Rate Access and Lender Pricing for Investors

Investor fixed rates are priced higher than owner-occupier fixed rates by 20 to 50 basis points, depending on the lender and the LVR. At an LVR above 80 per cent, the margin widens further and some lenders withdraw fixed rate availability altogether for investor loans. If you require Lenders Mortgage Insurance, you may be restricted to variable rate products or a small panel of lenders willing to offer fixed rates at elevated pricing.

Lender appetite for fixed rate investment lending also varies by property type. Units in Brisbane's inner suburbs, particularly buildings with more than 50 dwellings or a commercial component exceeding 20 per cent of the title, may be subject to additional credit overlays that remove access to fixed rates or reduce the maximum LVR. If you are purchasing in South Brisbane, Fortitude Valley or Newstead, verify the building is unaffected by any lender servicing restrictions before you commit to a fixed rate strategy. Some of those buildings are still affected by cladding reviews or are flagged internally by lenders due to high investor concentration.

Fixed rate investment loans are generally unavailable for properties classified as non-standard security, including properties on leasehold title with less than 30 years remaining, properties requiring commercial zoning approval, or dwellings located in regional or remote postcodes outside the lender's standard footprint. Brisbane investors purchasing in outer growth corridors such as Ripley or Flagstone may find fewer lenders willing to offer fixed rates compared to established inner and middle-ring suburbs.

Refinancing Investment Loans at Fixed Rate Expiry

When your fixed rate investment loan expires, the loan automatically reverts to the lender's standard variable rate unless you proactively refinance or negotiate a new fixed term. The standard variable rate for investors is typically 50 to 80 basis points higher than the lender's discounted variable rate offered to new borrowers. Over 12 months on a $600,000 loan, that margin costs an additional $3,000 to $4,800 in interest.

Refinancing at fixed rate expiry allows you to access current market pricing and reassess your loan structure. If your property has increased in value and your LVR has dropped below 80 per cent, you may now qualify for a lower rate band or regain access to interest-only repayments that were unavailable when you first borrowed. Refinancing your investment property is the point at which most investors also consider extracting equity to fund a deposit on the next property, provided serviceability allows and the portfolio strategy supports further leverage.

If you hold multiple investment properties and your fixed rates are expiring at different times, stagger the refinance rather than consolidating everything at once. Refinancing one property per year spreads your exposure to rate movements and avoids locking your entire portfolio into a fixed rate at a single point in the cycle. It also preserves flexibility to respond to changes in your income, portfolio performance or lending policy without triggering break costs across multiple loans.

Tax Treatment of Fixed Rate Loan Costs

Interest on an investment loan, whether fixed or variable, is deductible against rental income in the year it is incurred, provided the property is rented or genuinely available for rent. If you borrow additional funds against the investment property for private purposes, such as funding a holiday or purchasing a car, the interest on that portion is not deductible regardless of the security provided. Loan structures need to be documented carefully to preserve the deduction.

Break costs incurred when refinancing or discharging a fixed rate investment loan are deductible over the remaining fixed term or five years, whichever is shorter. If you incur a break cost of $15,000 with three years remaining on the fixed term, you can claim $5,000 per year over the next three years. The deduction is claimed under section 25-25 of the Income Tax Assessment Act 1997 (Cth) and applies only to investment loans, not owner-occupied debt.

For investors who acquired established residential property after 12 May and are now subject to the new negative gearing rules from the 2027-28 income year, interest deductions on those properties can only be offset against other residential property income, including capital gains on residential property. Losses are quarantined and carried forward. Investors who purchased before that date, or who purchased eligible new builds after that date, continue to deduct losses against all income. The legislation grandfathers properties held at 7:30pm AEST on 12 May and properties under contract at that time, even if settlement occurred later. Fixed rate loan costs, break costs and all other holding costs follow the same quarantine rules as interest once the new regime applies.

Call one of our team or book an appointment at a time that works for you to review your fixed rate options, model the impact on your borrowing capacity and structure the loan to align with your next portfolio move.

Frequently Asked Questions