How Much Does an Offset Account Actually Save?
An offset account is an everyday transaction account linked to your home loan. The balance sitting in it is subtracted from your loan balance before daily interest is calculated — $40,000 in offset against a $750,000 loan means you pay interest on $710,000.
It is probably the most underused feature in Australian mortgages, because the benefit is invisible: no interest is paid to you, so nothing shows up on a statement. What actually happens is better — interest that would have left your pocket simply never gets charged.
How it works
Money in an offset "earns" your mortgage rate, tax-free. A savings account paying 4% loses a slice to income tax at your marginal rate; an offset against a 6.2% loan avoids 6.2% interest, and avoided interest is not taxable income. For most borrowers the offset return beats any savings account on the market — with zero risk and instant access.
Because interest is calculated daily, every day your salary, emergency fund, or holiday savings sit in the offset, they are cutting that day’s interest. The loan repayment stays the same, so more of each repayment goes to principal, and the loan ends years early.
Priya keeps $40,000 in a high-interest savings account — after tax, it earns around $1,000 a year. Moved into an offset, the same cash blocks interest worth almost three times that. Same money. Same access. Different math.
The worked example
The numbers on this page model a $750,000 loan at 6.2% over 30 years — a realistic Australian mortgage. Here is what changes when you apply the strategy (offset balance: $40,000):
| Bank’s plan | With this strategy | Difference | |
|---|---|---|---|
| Time to pay off | 30.0 years | 26.7 years | −3.3 years |
| Total interest paid | $903,666 | $718,328 | −$185,338 |
Drag the slider to change the assumption and watch the payoff date move:
How to do it
- Check whether your loan has an offset facility, or what it costs to add one (some lenders charge a package fee — model whether the fee is worth it for your balance).
- Have your salary paid directly into the offset, and keep your emergency fund there instead of a savings account.
- Spend from it normally — the benefit comes from the average daily balance, not from locking money away.
- Model your own balance in the calculator to see the interest and years it removes.
Watch-outs
- Offset accounts are usually only available on variable-rate loans, and sometimes only with a package fee — check the fee doesn’t eat the benefit at small balances.
- A redraw facility is not the same thing: redraw money is technically the bank’s, access can be restricted, and using it has tax implications on investment properties.
- The benefit only exists while money is actually in the account — an offset with $500 in it saves almost nothing.
Frequently asked questions
Is an offset account better than a high-interest savings account?
For most owner-occupiers with a mortgage, yes. Savings interest is taxed at your marginal rate, while offset "returns" are tax-free avoided interest at your mortgage rate — typically 1.5–2.5% higher than savings rates to begin with. A 6.2% tax-free return with instant access is very hard to beat.
What’s the difference between an offset account and redraw?
Both reduce interest the same way, but offset money is yours in a transaction account you control, while redraw is extra repayment sitting inside the loan that the lender lets you take back. Lenders can restrict redraw access; they cannot restrict your offset. For investment properties the tax treatment also differs significantly — offset is generally cleaner.
Does a 100% offset account shorten the loan term?
Not by itself — your scheduled repayment stays the same, but because less of each repayment is consumed by interest, more goes to principal, so in practice the loan finishes years early. The calculator shows exactly how many years for your balance.
Is it worth paying a package fee to get an offset?
It depends on your average balance. As a rough rule, the annual interest saved is your offset balance times your rate — $20,000 offset at 6% saves about $1,200 a year, which comfortably beats a $395 fee. Below roughly $7,000–$10,000 in average balance, the fee can eat the benefit.