Rate Lock-ins and Break Costs: The Pros and Cons

What a Rate Lock-in Actually Gives You

A fixed rate on an investment loan locks your interest rate for a set term, usually between one and five years. You'll pay the same rate for that period regardless of what happens in the broader market.

That certainty helps when you're buying your first investment property and want predictable repayments, or when you're holding a negatively geared asset and need to forecast your after-tax position accurately. The downside is that you're contractually committed to that rate. If you want to exit early, refinance to access equity, or switch to interest-only, you'll likely face break costs.

How Break Costs Are Calculated

Break costs compensate the lender for the difference between the fixed rate you're paying and the rate they can now charge on the funds they've lent you. If rates have fallen since you fixed, the lender loses income when you leave early. That loss is passed to you as a break cost.

The formula considers the remaining fixed term, your outstanding loan balance, and the difference between your fixed rate and the current wholesale cost of funds for the same period. A borrower who fixed $600,000 at 5.2 per cent for five years and exits after two years when the three-year wholesale rate is 4.1 per cent could face break costs in the range of $15,000 to $25,000, depending on the lender's methodology.

If rates have risen since you fixed, break costs are usually nil. Some lenders may still charge an administration fee, but the economic loss component disappears.

When Refinancing Makes Sense Despite the Cost

Break costs don't always mean you should stay put. If you're refinancing to a lower interest rate and the ongoing saving exceeds the upfront cost within a reasonable period, the switch can still work.

Consider a Flinders investor with a $750,000 loan fixed at 5.6 per cent, with three years remaining on the fixed term. The break cost estimate comes back at $22,000. They've been offered a variable rate at 4.9 per cent. The difference is 0.7 percentage points, which saves roughly $5,250 per year on a principal-and-interest loan. The break cost is recovered in just over four years. If they plan to hold the property for another decade, the refinance works financially.

What changes the outcome is time horizon and loan structure. If the same borrower is planning to sell within two years, the break cost isn't recovered. And if they're on interest-only, the saving shrinks because the loan balance doesn't reduce as quickly.

The Partial Fix Option

Some lenders allow you to split your investment loan into fixed and variable portions. You might fix 60 per cent of the balance and leave 40 per cent variable. That gives you partial rate protection while keeping flexibility to make extra repayments, access offset, or refinance part of the debt without triggering the full break cost.

In our experience, this structure suits investors who want stability but also plan to release equity down the track or pay down part of the loan using rental income or bonuses. It's not offered universally, and pricing can vary, but it's worth comparing if you're weighing up fixed versus variable.

Rate Lock-ins and the Current Legislation

From the 2027-28 income year, investment loan refinancing decisions will be shaped by the new negative gearing rules. Established properties purchased after 12 May 2026 can only claim rental losses against other residential property income. Properties held before that date, and eligible new builds purchased after it, can still offset losses against salary or business income.

That distinction affects refinancing strategy. If you're holding a grandfathered property with full negative gearing access, refinancing to a lower rate preserves that tax treatment and increases the deductible interest component if you're borrowing to release equity for another investment. If you're buying an established property now, the tax benefit of high interest costs is more limited, which shifts the focus toward minimising the rate itself rather than maximising the deduction.

Break costs don't change based on the tax treatment of the loan, but the value of staying in a higher fixed rate versus moving to a lower variable rate does change when your ability to offset the interest is restricted.

What Lenders Don't Always Explain Upfront

Most lenders provide a break cost estimate before settlement, but the figure is indicative only. The actual cost is calculated on the day you discharge the loan, using the wholesale rate at that moment. A rate shift of 0.1 percentage points can move the break cost by several thousand dollars.

Some lenders also apply break costs to partial repayments above a certain threshold during the fixed term, even if you're not refinancing. If your fixed loan allows up to $10,000 in extra repayments per year and you pay $30,000, the excess $20,000 may trigger a proportional break cost. That's not common across all products, but it's worth confirming before you commit to a fixed rate if you expect irregular income from bonuses or asset sales.

Fixed Rates and Interest-Only Investment Loans

Many investors fix their loan on an interest-only basis to maximise the tax deduction and preserve cash flow. The fixed term and the interest-only term don't always align. You might fix for three years but only have interest-only approved for five. At the end of the fixed period, the loan typically reverts to variable, and if the interest-only period is still active, you continue paying interest only at the new rate.

If the interest-only period expires before the fixed term ends, the loan converts to principal-and-interest while still locked at the fixed rate. Your repayment jumps, sometimes significantly, because you're now paying down the balance. That can create a serviceability issue if you're holding multiple properties or relying on rental income to cover most of the cost.

When structuring a fixed-rate investment loan, make sure the interest-only term at least matches the fixed term, and preferably runs longer. That gives you the option to revert to variable and extend interest-only at the same time if your strategy or circumstances change.

The Portability Clause You Should Ask About

Some lenders offer portability, which lets you transfer your fixed-rate loan to a new property without breaking the contract. If you sell your Flinders investment and buy another within a short window, usually 90 days, the fixed rate moves across to the new security. You'll still need to meet current serviceability rules, and if the new loan amount is higher, the additional borrowing is typically priced at the current rate, not the old fixed rate.

Portability isn't standard, and it's rarely mentioned unless you ask. It's particularly relevant if you're planning to trade up within your portfolio or relocate interstate but want to keep the fixed rate you locked in when conditions were more favourable.

Call one of our team or book an appointment at a time that works for you. We'll walk through your current loan structure, calculate whether a break cost is worth wearing, and help you weigh up fixed, variable, or split options that actually suit the way you're building your portfolio.

Frequently Asked Questions