Do You Know When to Fix Your Investment Loan?

A fixed rate on an investment loan offers certainty, but whether you lock in for one year or five depends entirely on where you are in life.

Your borrowing capacity, your income stability, your portfolio goals and your ability to absorb rate movements all shift as you move from early career to peak earning years and then into retirement planning. The structure that makes sense when you're 32 and adding properties rarely suits someone at 55 preparing to wind down. Locking in the wrong term at the wrong stage can leave you unable to refinance, unable to access equity, or paying break costs that wipe out years of tax deductions.

Why Your Life Stage Changes the Fixed Rate Decision

A fixed rate investment loan removes rate risk for the chosen term, but it also removes flexibility.

In your 30s, you're often building a portfolio and need the ability to refinance, access equity or adjust your loan structure as your income and property values change. A long fixed term can trap equity and make it costly to pivot. In your 40s and 50s, income is typically higher and more stable, borrowing capacity is at its peak, and a longer fixed term can lock in predictable repayments without the same opportunity cost. Approaching retirement, the focus shifts to paying down debt and protecting against rate rises on a fixed income, which changes the calculation again.

The loan structure that suits each stage is different, and choosing poorly can cost you both money and opportunity.

Building a Portfolio in Your 30s and Early 40s

When you're adding properties, flexibility matters more than rate certainty.

Consider an investor who purchases a two-bedroom unit in Cheltenham at age 34 with a 20 per cent deposit and an investment loan of $520,000. She earns $95,000 and plans to buy a second property within three years using equity from the first. If she fixes the entire loan for five years at the time of purchase, she will face break costs if she needs to refinance to access that equity. Those costs depend on the difference between her fixed rate and the lender's current wholesale rate at the time of exit, and in a falling rate environment they can exceed $15,000. She also cannot split the loan or move to interest-only repayments without breaking the fixed term.

A shorter fixed term, or a 50/50 split between fixed and variable, preserves the ability to refinance the variable portion, access equity as the property appreciates, or adjust repayment structures without penalty. At this stage, most investors we work with either fix for one to two years only or split the loan, keeping at least half on variable. The variable portion provides a release valve.

Locking In Certainty During Peak Earning Years

When your income is high and stable, a longer fixed term makes more sense.

An investor at age 48 with an established portfolio of three properties and a combined loan balance of $1.1 million earns $160,000 in a senior role. He has no plans to purchase further properties in the next five years and wants to protect his cashflow against rate rises. His rental income covers most of his repayments, but a two percentage point rise in variable rates would push him into negative cashflow of $1,800 per month. Fixing the majority of his debt for three to five years removes that risk and allows him to budget with confidence. At this stage, the flexibility cost of a longer fixed term is lower because he is not actively adding to the portfolio and his borrowing capacity is sufficient to absorb future changes without needing to refinance.

Some investors at this stage still split their loans, fixing 70 to 80 per cent and leaving a smaller variable portion for offset access and early repayments. A refinance is still possible on the variable portion if a better rate appears, and break costs are limited to the fixed portion only.

Transitioning Toward Retirement in Your Late 50s and 60s

As you approach retirement, the priority shifts to debt reduction and income protection.

An investor at 58 with two properties in Mentone and Brighton East holds $680,000 in investment debt. She plans to retire at 65 and wants to sell one property and pay down the other before her income drops. She no longer benefits from negative gearing because her taxable income will fall, and she needs to minimise interest costs rather than maximise tax deductions. Fixing the loan for a short term of one to two years gives her rate protection without locking her into a structure that penalises early repayment when she sells. She can also move part of the loan to principal and interest repayments without triggering break costs if she splits the loan and only fixes the portion she intends to hold.

At this stage, interest-only terms are harder to justify. Lenders assess investment loan serviceability more conservatively as you near retirement, and moving to principal and interest reduces risk and total interest paid. A loan health check before fixing allows you to confirm your repayment structure suits your exit strategy, not just your current cashflow.

What Happens If You Lock In at the Wrong Time

Break costs are calculated using the difference between your fixed rate and the lender's current cost of funds, multiplied by the remaining term.

If you fixed at 5.8 per cent for five years and want to exit after two years when the equivalent fixed rate has dropped to 4.6 per cent, the lender has lost the benefit of the higher rate for the remaining three years. They calculate the present value of that loss and charge it to you. On a $500,000 loan, that cost can range from $8,000 to $20,000 depending on the rate gap and remaining term. That calculation is not always transparent, and many borrowers only discover the cost when they request a payout figure.

If you split your loan and only fix part of it, break costs apply only to the fixed portion. You can refinance or access equity through the variable portion without penalty, which is why splitting is the default structure we recommend for most investors under 50.

How the New Negative Gearing Rules Affect Fixed Rate Choices

From 1 July 2027, properties purchased after 7:30pm on 12 May 2026 can no longer offset rental losses against wage income unless they are eligible new builds.

This changes the fixed rate decision for new investors. If you cannot claim the full interest deduction against your salary, the cashflow benefit of a lower fixed rate becomes more important because you are funding the shortfall from after-tax income. A longer fixed term that locks in a lower rate can reduce your monthly out-of-pocket cost by hundreds of dollars, which matters more when that cost is no longer tax-deductible.

For properties purchased before that date, full negative gearing remains available, and the fixed rate decision is still driven by flexibility and portfolio strategy rather than cashflow alone. If you are considering a purchase in the next 12 months, the timing of settlement and the structure of your fixed rate should be considered together.

Should You Ever Fix an Entire Investment Loan?

Fixing 100 per cent of an investment loan removes all flexibility and only makes sense in specific circumstances.

If you are holding a single property long-term with no intention to access equity, refinance, or change repayment structures, and you want complete certainty over repayments, a full fix can work. But even in that scenario, a small variable portion of 10 to 20 per cent preserves the ability to make extra repayments into an offset account, which you cannot do on a fully fixed loan. Most lenders allow additional repayments of up to $10,000 per year on a fixed loan without penalty, but anything beyond that incurs a charge.

Splitting gives you the certainty of a fixed rate on the majority of the loan without losing all access to flexibility, offset benefits, or early exit options. It is the most common structure across all life stages, with the split ratio adjusted depending on your goals.

If you are building a portfolio, refinancing within the next few years, or planning to access equity, a fixed rate should be a tool within your loan structure, not the entirety of it. If you are in peak earning years with no immediate plans to change your holdings, a longer fixed term on a higher proportion of the loan can deliver cashflow certainty without the same opportunity cost. And if you are preparing for retirement, a short fixed term on a loan you plan to reduce or exit protects you from rate rises without penalising your strategy.

Call one of our team or book an appointment at a time that works for you.

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