Offset Accounts: How They Actually Work and How to Use Them Properly
We sat down with a client last month to do an annual review on his loan. Variable rate, 25 years left, $620,000 balance. He'd had an offset account attached to his loan since settlement in 2022 and assumed it was working. When we asked what his average offset balance was, he wasn't sure. He had a quick look on his banking app and found out he'd been holding about $4,000 in there because most of his savings sat in a separate high-interest account at a different bank.
That $4,000 had been saving him roughly $250 a year in interest. The $80,000 sitting in his high-interest savings account next door, earning around 4.5% pre-tax (around 2.7% after tax for him), could have been saving him roughly $5,000 a year if it had been in the offset instead. Same money. Wildly different outcomes.
Offset accounts are one of the most powerful features in Australian home loans, and one of the most underused. If you've got one and you're not sure you're using it well, or if you're not sure whether you should have one at all, this piece is for you.
What an Offset Account Actually Is
An offset account is a transaction account linked to your home loan. The balance in the offset reduces the loan balance the lender calculates interest on. You don't earn interest on the offset balance. Instead, the money in it effectively earns the same rate as your home loan rate, tax-free, by reducing the interest you'd otherwise pay.
The mechanics are simpler than they sound. If your loan balance is $600,000 and your offset balance is $50,000, the lender calculates interest on $550,000 rather than $600,000. The loan term and the contractual repayment don't change, but more of each repayment goes toward principal because less is being eaten by interest.
The compounding effect over a 25 or 30-year loan is significant. A consistent $50,000 offset balance against a $600,000 loan at around 6.25% saves roughly $3,100 per year in interest in the early years of the loan, and shaves around three to four years off the total loan term if maintained consistently.
Offset vs Redraw: They're Not the Same Thing
A common source of confusion. Both offset and redraw effectively let extra money sitting against your loan reduce interest. They work differently though, and the differences matter.
Offset is a separate transaction account. The money in it is yours to access at any time as if it were a normal bank account. You can have a debit card linked to it, pay bills from it, receive your salary into it. The lender doesn't have to approve anything when you take money out. The trade-off is that loans with offset accounts often have slightly higher rates or annual fees compared to basic loans without.
Redraw is access to the extra repayments you've made on the loan itself. If your contractual repayment is $3,800 a month and you've been paying $4,200 a month, the extra $400 a month sits in the loan as accumulated extra repayments. You can usually pull that money back out, but it requires a redraw transaction, which some lenders limit, charge for, or require approval for. The money is technically not yours, it's a refund of overpayments.
The tax implications are the bigger distinction. For owner occupiers, the two are economically similar. For investment loans, there's a meaningful difference. Money held in an offset account against an investment loan doesn't affect the tax-deductibility of the loan interest. Money pulled out via redraw on an investment loan can affect the deductibility, because the ATO treats redraw as a new borrowing for whatever purpose you use it for.
The practical implication: if you've got an investment property, the offset account is almost always the right structure. Mixing personal money in and out of an investment loan via redraw is one of the most common ways investors accidentally damage their tax position. Worth a conversation with your accountant before you start moving money around either way.
What an Offset Account Costs (And Whether It's Worth It)
Loans with offset accounts typically cost a bit more than basic no-frills loans. The difference shows up either as a slightly higher rate (often 0.10% to 0.30% above a basic equivalent) or as an annual package fee (often $300 to $400 a year for a package that includes the offset, a credit card, fee waivers, and sometimes other features).
Whether the offset is worth that premium depends on the average balance you'd realistically hold in it. A rough rule of thumb:
If your offset balance averages around $15,000 to $20,000 or more over the year, the offset usually pays for itself comfortably. The interest saving exceeds the rate or fee premium.
If your offset balance averages under $10,000, the maths is closer. The interest saving may or may not cover the premium, depending on your specific loan rate and the structure of the package fee.
If you're between, it depends. The other features in the package (fee-free credit card, banking discounts, multiple offset accounts, fee waivers) may make the package worth it even when the offset balance alone wouldn't justify it.
We work through the maths with clients regularly. For most borrowers with reasonable cash flow, the offset earns its keep. For borrowers who genuinely don't accumulate savings (or whose savings sit elsewhere for specific reasons), a basic loan can be the cheaper choice.
How to Use an Offset Properly
A few practical patterns that genuinely move the needle.
Have your salary paid directly into the offset. This is the single biggest leverage point most borrowers miss. Your salary lands in the offset, sits there reducing interest until you spend it, and you pay everything (including the credit card bill at month-end) from the offset. Even if your balance is low by the end of the month, the average balance throughout the month is meaningful.
Use a credit card with an interest-free period for daily spending. Pay all your bills and groceries on a credit card, then pay the full balance off from your offset on the due date. Your cash effectively sits in the offset for an extra 30 to 50 days rather than being spent immediately. Done right, this lifts your average offset balance by a meaningful amount without changing your spending.
Don't park large savings elsewhere unless there's a reason. The most common pattern we see is borrowers with $30,000 to $100,000 sitting in a high-interest savings account next door to their mortgage. The savings account pays around 4% to 5% pre-tax, which is roughly 2.5% to 3% after tax for most earners. The offset effectively pays your home loan rate (around 6% to 7%), tax-free. The maths almost always favours the offset.
Exceptions exist. Money you genuinely need ringfenced (for example, an SMSF contribution, a separate household member's funds, money earmarked for tax that needs to be visible for accounting purposes) might stay in a separate account for good reasons. The point is that the choice should be deliberate, not accidental.
Set up multiple offset accounts if your lender allows. Some lenders let you have multiple offset accounts attached to a single loan. This can be useful for separating savings buckets (a holiday fund, an emergency fund, a renovation fund) while still getting the full interest benefit of the combined balance. Functionally identical to having the same money in one account, but easier to manage psychologically.
Watch out for "partial offset" accounts. Most major banks offer 100% offset accounts where every dollar in the offset reduces interest by an equivalent amount. A few lenders offer "partial offset" accounts where only a portion (often 40% to 80%) of the offset balance counts. These are almost always worse value than a full offset and worth avoiding unless there's a specific reason.
Common Mistakes That Reduce the Benefit
The patterns we see most often.
Keeping the offset balance too low. As above, the salary-into-offset and credit-card-for-spending combination is the simplest way to lift the average balance. Most borrowers who say "the offset doesn't do much for me" haven't actually optimised the cash flow.
Pulling money out of the offset for short-term reasons without thinking it through. Every dollar you take out of the offset is a dollar earning your home loan rate. If you're using it for a $5,000 holiday, the holiday is effectively costing you the $5,000 plus the interest you'd have saved by leaving it there.
Having an offset on the wrong loan in a split structure. If you've got a split loan (part fixed, part variable), the offset can only be attached to the variable portion. Make sure the split sizing puts enough debt on the variable side to absorb the offset balance. An offset of $200,000 against a $150,000 variable portion only effectively offsets $150,000 of debt, with the other $50,000 of cash earning nothing.
Mixing personal and investment money in an investment loan offset. This is the investor-specific version of the deductibility problem mentioned earlier. If you've got an offset account against an investment loan, keep the money flow clean. Don't use it as your everyday transaction account if other personal money is moving through it. Speak to your accountant about the best structure for your specific situation.
Forgetting the offset exists. Sounds obvious. Happens often. Annual reviews with a broker should always check offset usage as part of the conversation.
Where We Come In
If you're not sure whether your offset is working as hard as it could, or whether your loan structure is right for the cash flow you've got, an annual review is exactly the conversation worth having. We look at the average balance you're holding, the structure of the loan, the way your cash flow is set up, and whether a different loan structure would suit you better.
If your loan doesn't currently have an offset and you've got savings sitting in a separate account earning less than your mortgage rate, the question is whether restructuring is worth it. Sometimes refinancing to add an offset facility is the right call. Sometimes it isn't. The maths is genuinely specific to your situation.
If you've got an investment loan and you're not sure your money flow is set up cleanly, that's a particularly worthwhile conversation to have before the ATO becomes the one asking questions.
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