By Paul Feeney, Founder and Chief Executive Officer, Otivo
An offset account could save you thousands in home loan interest while keeping your savings within reach. But there's a catch. Here's how to work out whether yours is earning its keep.
There's something appealing about the idea of making your savings work harder without doing anything particularly clever. No investing, no market risk, no complicated strategy. Just money sitting in a bank account, quietly helping you pay off your mortgage faster.
That's the promise of a mortgage offset account. And with a home loan likely to be one of the biggest financial commitments you'll ever make, anything that reduces the interest you pay sounds like a pretty good deal.
But here's what the banks don't always make obvious: simply having an offset account doesn't save you a cent. What matters is how much money you actually keep in it, how long it stays there and what you're paying for the privilege.
Get that balance right, and an offset could save you thousands. Get it wrong, and you could be paying extra for a feature that's barely doing anything.
First, how does an offset account actually work?
Think of an offset account as an everyday bank account with a useful trick up its sleeve.
It looks and behaves much like a regular transaction account. You can deposit your salary, pay bills, transfer money and access your savings whenever you need them.
The difference is what happens behind the scenes.
Your offset balance is linked to your mortgage and reduces the amount of your home loan on which the bank calculates interest.
Say you've got a $400,000 mortgage with an interest rate of 6% and $30,000 sitting in a 100% offset account.
Instead of calculating interest on the full $400,000, your lender calculates it on $370,000.
Assuming that balance stays the same for an entire year, that's approximately $1,800 less in interest.
The important part? Your $30,000 hasn't gone anywhere. It's still sitting in your account, ready to use if the car breaks down, the roof starts leaking or life throws something unexpected your way.
The more you keep in it, the more you save
This is where offset accounts start to get interesting.
At a 6% home loan interest rate, every $10,000 you consistently hold in a full offset account could save you approximately $600 in interest over a year.
Keep $20,000 in there, and that's around $1,200. Maintain a balance of $50,000, and you're looking at approximately $3,000 in annual interest savings.
And those savings can add up.
If your regular mortgage repayments stay the same, less money going towards interest means more can go towards reducing the loan principal. Over time, that could help you pay off your mortgage sooner.
But there's a catch.
Most of us don't have tens of thousands of dollars sitting untouched in a bank account. Our balances rise when we're paid and fall as bills, groceries and everyday expenses come out.
Because mortgage interest is generally calculated daily, it's your daily offset balance that matters, not the amount you had in there on payday.
Which means a $30,000 offset balance that lasts just a few days won't deliver anything close to $1,800 in annual savings.
The real benefit comes from keeping money in the account consistently, even if the balance isn't particularly large.
Why not just make extra mortgage repayments?
It's a fair question. After all, putting an extra $30,000 directly into your mortgage can also reduce the interest you pay.
So why bother with an offset?
One word: flexibility.
Extra repayments reduce your outstanding loan balance. Depending on your lender and loan conditions, you may be able to access those funds through a redraw facility. But redraw isn't always as straightforward as withdrawing money from a bank account.
With an offset, your savings remain separate from the mortgage and are generally available whenever you need them.
That makes it particularly appealing if you're building an emergency fund, saving for renovations or simply want a financial buffer without sacrificing the opportunity to reduce your home loan interest.
It's a way of putting your savings to work while keeping them within reach.
And there's another consideration. If you eventually decide to turn your home into an investment property, the way you've managed extra repayments and redraw can have tax implications. An offset account may offer advantages in some circumstances, although the right approach depends on your situation and is worth discussing with a qualified tax professional.
But an offset account isn't always worth paying for
Here's where the story changes.
Not every offset account comes free. Some lenders charge an annual package fee, while others offer offset facilities only on loans with higher interest rates.
And those extra costs can quickly eat into your savings.
Imagine two home loan options. One has a 6% interest rate with no offset account. The other offers an offset but charges an additional $300 a year, with the same interest rate.
If you typically keep $3,000 in your offset, you'd save approximately $180 in interest over a year.
That's $180 saved, but $300 spent.
You're effectively $120 worse off.
Of course, if you regularly hold $20,000 in that same account, the numbers look very different. Your approximate annual interest saving would be $1,200, leaving you $900 ahead after the fee.
The lesson? An offset account isn't automatically a good deal. It has to earn its keep.
And if the offset loan also comes with a higher interest rate, the calculation becomes even more important because that higher rate can apply to a substantial portion of your mortgage.
So, how much do you need in an offset to make it worthwhile?
There's no magic number. It depends on your interest rate, the fees you're paying and the alternative home loans available.
But you can make a useful first estimate.
At a 6% interest rate, a $300 annual offset fee would require an average balance of around $5,000 just to cover that fee through interest savings, assuming the alternative loan has the same interest rate.
Anything above that could put you ahead. Anything below it, and the fee could outweigh your savings.
Of course, real home loans aren't always that simple. Different interest rates, loan features and fees can change the equation.
That's why it's worth comparing the total cost of a loan with an offset against a comparable loan without one, rather than focusing on the offset feature in isolation.
And remember, the amount you plan to save isn't necessarily the amount you'll keep in your account. Base your calculations on what you can realistically maintain.
One more thing: is your offset actually working?
Here's something many homeowners might not think to check.
Just because you've opened an offset account doesn't necessarily mean it's been correctly linked to your mortgage.
ASIC has previously identified problems involving offset accounts that weren't properly connected to home loans, resulting in some customers paying more interest than they should have.
It's a useful reminder that setting up an offset account shouldn't be the end of the story.
Check your home loan statements, confirm that your offset balance is being applied correctly and ask your lender to explain how your interest is calculated if something doesn't look right.
After all, there's not much point keeping thousands of dollars in an offset account if it isn't actually reducing your interest.
Four things to check before opening an offset account
Before signing up, it's worth asking a few questions.
1. Is it a 100% offset?
Some accounts only offset a portion of your balance against your mortgage. A full offset generally provides a greater interest reduction, so make sure you understand exactly what you're getting.
2. What does it actually cost?
Look beyond the advertised interest rate. Check annual package fees, monthly account fees and whether a comparable loan without an offset offers a lower rate. Even a small difference can add up over the life of a mortgage.
3. How much will you realistically keep in it?
Think about your average balance over the month, not just how much money comes in on payday. If your account is regularly close to empty, the savings may be smaller than you expect.
4. How will you use the account?
If you're building savings or maintaining an emergency fund, the accessibility may be valuable. If you're unlikely to keep much cash available, the benefits could be limited.
The bottom line: it's not the account, it's what you do with it
An offset account can be a genuinely useful tool for reducing mortgage interest without giving up access to your savings.
But it's not a shortcut, and it's certainly not free money.
The real value comes from consistently keeping enough money in the account to make the interest savings worthwhile after fees and any higher loan rate.
Before paying extra for an offset, do the maths using your actual savings habits, not the balance you hope to have one day.
Because the best home loan feature isn't necessarily the one with the most benefits on paper. It's the one that genuinely leaves you better off.
Sources
- ASIC Moneysmart — Mortgage offset accounts. How offset accounts work, interest savings, fees and comparison with redraw facilities.
- ASIC Moneysmart — Pay off your mortgage faster. Strategies for reducing home loan interest through extra repayments and offset accounts.
- ASIC Moneysmart — Choosing a home loan. Comparing mortgage interest rates, fees and loan features.
- Australian Taxation Office. Guidance on interest deductibility, redraw facilities and rental property loans.
- Australian Securities and Investments Commission. Regulatory information and reporting concerning mortgage offset account administration.
Frequently asked questions
Is an offset account worth it?
It's worth it when you maintain a meaningful balance, since the interest saving scales with what you keep in the account. It's less worthwhile with a consistently small balance or when the loan charges a higher rate or fee for the feature.
Is an offset better than extra repayments?
They have a similar interest-reducing effect, but an offset keeps your money accessible while extra repayments are harder to reverse. Which suits you depends on how much you value flexibility versus the discipline of paying down the loan.
Do offset accounts cost extra?
Some loans charge a higher interest rate or an annual fee for an offset feature. It's worth comparing that cost against the interest your typical offset balance would save, to check the feature pays for itself.
Where to from here
Whether an offset is worth it comes down to what you'll keep in it. Otivo, a licensed Australian financial advice platform holding AFSL and Australian Credit Licence No. 485665, offers a debt advice module that helps you find effective ways to manage and pay down debt while covering essentials, based on your debts, income and expenses. It helps you see whether an offset fits how you actually handle money.
Sources
- ASIC MoneySmart — offset accounts and home loans — moneysmart.gov.au
Disclaimer
The information in this communication is current as at July 2026 and has been prepared by Otivo Pty Ltd ABN 47 602 457 732, AFSL and Australian Credit Licence No. 485665. This content is general information only and has been prepared without taking into account your objectives, financial situation or needs. It is not personal financial or taxation advice and should not be relied on as such. Before acting on any information, you should consider its appropriateness having regard to your personal circumstances. This material must not be reproduced in whole or in part, or posted on any social media platform, without the prior written consent of Otivo Pty Ltd.