49 Lenders Drop Below 6%: Banks Pocket $11k From Loyal Borrowers

The mechanics behind this gap are straightforward. Major banks set headline rates for new customers to attract volume, then allow back-book rates — the rates charged to existing, long-standing borrowers — to drift. This "loyalty tax" functions as a silent transfer from passive borrowers to bank profit margins. It is not illegal. It is not hidden in fine print. It simply exploits the well-documented tendency of borrowers to underestimate the compounding cost of inertia. For property investors managing cash flow across one or multiple loans, this drag is especially damaging because it compounds against deductible interest calculations as well as net yield.

For owner-occupiers and investors alike, the practical implication is immediate: if you have not reviewed your mortgage rate in the past six months, you are statistically likely to be paying a loyalty premium. The $11,000 figure represents a real and quantifiable cost over a defined period — not a marginal monthly difference that can be dismissed. For an investor with two properties, the total cost of inertia could be materially higher. Refinancing does carry some upfront costs, and borrowers should factor these into any switching calculation.

This dynamic is not new to Australian banking. The Australian Competition and Consumer Commission has previously examined back-book versus front-book pricing differentials, and the practice of offering sharper rates to new customers while leaving existing borrowers on higher rates has been a persistent feature of the market. With 49 lenders now pricing below 6 per cent, the pool of alternatives for refinancing has never been broader.

What the Rate Gap Means for Property Investors' Tax Position

For negatively geared property investors, mortgage interest is the single largest deductible expense. The Australian Taxation Office allows investors to claim the interest component of their loan repayments as a tax deduction against rental income — and where rental income falls short of total expenses, the resulting loss can be offset against other assessable income. This means that the rate you pay on your investment loan directly determines both your cash flow burden and the size of your annual tax deduction. Paying a higher rate than necessary therefore carries a double cost: more cash out the door, and a deduction that reflects a structural inefficiency rather than genuine investment strategy.

With 49 lenders pricing home loans below 6 per cent, the gap between loyal-borrower rates at major banks and the sharpest available offers has produced a tangible, quantifiable cost — $11,000 — that borrowers who treat their mortgage rate as a fixed cost are leaving on the table in both cash flow and tax efficiency terms.

Investors should also consider the interaction between their loan rate and their depreciation schedule. A property depreciation schedule provides non-cash deductions — typically on plant and equipment and the building's capital works — that reduce taxable income without requiring additional cash outflow. When these deductions are combined with a competitively priced interest rate, the combined tax position can shift materially. Overpaying on interest, however, erodes the net cash benefit of those depreciation deductions by tightening cash flow in the years before a tax return is lodged.

Owner-occupiers cannot claim mortgage interest as a deduction, which means the $11,000 loyalty penalty is a purely after-tax cash cost. For investors, the sting is partially offset by the deductibility of interest — but only partially. A dollar overpaid in interest returns at most 47 cents via a tax deduction (for a top-rate taxpayer), meaning the net cash cost of inertia remains significant regardless of marginal tax rate. Acting on a better rate is almost always preferable to accepting a higher deduction at an elevated rate.

Background: The Loyalty Tax and Negative Gearing Mechanics

The concept of a "loyalty tax" sits at the intersection of mortgage pricing and investment property finance. For investors using negative gearing — where deductible expenses including interest exceed rental income — the rate paid on investment debt is not merely a financing cost but a core variable in the investment's tax and cash flow model. Our Negative Gearing vs Positive Gearing guide explains the full mechanics of how interest deductions interact with rental income and assessable losses, and is essential reading for any investor reviewing their loan structure this financial year. For the full breakdown of how interest, depreciation, and capital gains interact across a property portfolio, see our Australian Property Tax Guide.

The broader lending market context is also relevant. realestate.com.au has reported that CBA's profit has accelerated even as investor home loan volumes have dropped — a data point that underscores the profitability of holding existing borrowers on higher back-book rates while new loan origination slows. The major banks are not cutting rates out of competitive altruism; they are managing margin across a book where passive borrowers subsidise the sharpest front-book offers.