What Is an Offset Account and How Does It Work?
An offset account uses your savings to cut the interest on your home loan, every day, tax-free. Here is exactly how it works, what it costs, and who it suits.
By Timothy Hirou GaschereauPublished 10 min read
Try it yourself
An offset account is one of the most powerful features you can attach to an Australian home loan, and one of the most misunderstood. It quietly does big work in the background: your everyday savings cut the interest you owe, every single day, without locking a cent away.
Here is exactly how it works, the maths, what it costs, and whether it is worth it for you.
🎯 The essential: An offset account is a transaction or savings account linked to your home loan. The balance is offset against your loan principal, so you are only charged interest on the difference. On a $500,000 loan with $50,000 in offset, you pay interest on $450,000. The saving is effectively a tax-free return equal to your loan rate, which beats a savings account after tax, and the money stays fully accessible. The catch: offsets often carry a higher rate or annual fee, so the benefit needs to outweigh the cost. This is general information, not personal advice.
What an offset account is
An offset account is a transaction or savings account linked to your home loan. The balance sitting in it is "offset" against your outstanding loan principal, so you are charged interest only on the difference. It is not a separate investment or a term deposit, just a bank account that sits alongside your mortgage. Most offsets are everyday accounts you can use for direct debits, EFTPOS and transfers exactly like normal. The only difference is your lender checks the balance each day before working out your interest.
How it works
Home loan interest is calculated daily, and with an offset the daily sum becomes:
Interest charged = (loan balance minus offset balance) x daily rate
The mechanic people miss: your minimum repayment does not change. But because less of each repayment goes to interest, more chips away at the principal, so the loan shortens over time without you paying a cent extra each month. Try the numbers in our offset account calculator.
Why it is so powerful
- A tax-free effective return. The interest you save is not taxable income. At a 32.5% marginal rate, a 6% loan rate is like a savings account paying about 8.9% gross, and most savings accounts pay well below that (and you are taxed on what they do pay).
- Your money stays fully accessible. Unlike extra repayments (which sit inside the loan and need a redraw to get back), offset money is yours instantly, no application or lender approval.
- Every dollar works from day one. Even $500 saves interest daily, with no minimum balance. Your salary landing on Wednesday starts saving you interest on Wednesday.
Offset vs redraw vs savings account
| Offset account | Redraw | Savings account | |
|---|---|---|---|
| What it is | Linked everyday account | Extra repayments in the loan | Standalone savings account |
| Tax on the benefit | Tax-free (you save interest) | Tax-free (you save interest) | Taxable at your marginal rate |
| Access to funds | Instant, like any account | Depends on lender; fees/limits possible | Instant (some notice periods) |
| Investor tax risk | Preserves deductible loan balance | Redraw for private use can reduce deductibility | Not applicable |
For investors this distinction is critical: keeping cash in an offset against an investment loan preserves the full deductible balance, whereas redrawing extra repayments for personal use can contaminate the deductible portion. Our offset vs redraw guide and tax on savings interest go deeper.
100% offset vs partial offset
A 100% offset means your full balance offsets the loan (the common, most valuable type). A partial offset only counts a portion, say 40%, so $50,000 might offset just $20,000. Offsets are almost always available on variable-rate loans only; some lenders offer a partial offset on fixed portions, and on a split loan you can typically only offset the variable part. If you are on a fixed rate and want the benefit, check exactly what your lender offers before assuming it is working in full.
The catch: costs and trade-offs
Be honest about the downsides, because they are real:
- A higher rate. Offset loans often carry a rate 0.1 to 0.3% above a basic variable loan. On $500,000, an extra 0.2% is $1,000 a year your offset savings must beat.
- Annual package fees, commonly $300 to $400 (a $395 fee is typical).
Run the break-even. A $395 fee divided by a 6% rate means you need about $6,583 sitting in the offset permanently just to cover the fee, before you save a cent. If your balance is consistently below that, the fee costs more than the feature saves. The offset earns its keep once you keep a meaningful balance there, your salary, emergency fund and short-term savings all in the one account.
Smart ways to use one
- Direct your salary into it, so your pay reduces interest from the day it lands, even if you spend it by month's end.
- Park your emergency fund there instead of a taxable savings account; it earns a tax-free return equal to your loan rate and stays just as accessible.
- Hold short-term savings there (holiday, car, reno), all reducing interest while they sit.
- Use a linked credit card for monthly spending (paid in full every month) and sweep it from the offset at the end, keeping your cash offsetting for longer. Only if you clear the card, since card interest wipes out the benefit.
- Investors: keep cash in the offset, not the loan, to preserve deductibility. See investment property tax deductions.
Pairing an offset with a plan to pay off your mortgage faster is where the real gains compound.
Frequently asked questions
Is an offset account the same as a savings account?
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No. A savings account earns interest, which is taxable income. An offset account does not earn interest; it reduces the interest charged on your home loan. Because the saving is tax-free, an offset often works out more valuable than a savings account on an after-tax basis, and it is linked to your loan rather than standalone.
Does an offset account reduce my loan balance?
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Not directly. Your loan balance stays the same on paper. What changes is the balance interest is calculated on each day. Because less of each repayment goes to interest, more goes to principal over time, so the loan is paid off sooner.
Can I have an offset account on a fixed-rate loan?
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Generally no. Full 100% offset accounts are almost always only available on variable-rate loans. Some lenders offer a partial offset on fixed-rate portions, and on a split loan you can typically only offset against the variable portion. Always check your lender's terms.
Is the money in my offset account safe?
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Yes, subject to the same protections as any Australian bank account. Deposits with authorised deposit-taking institutions are protected under the Financial Claims Scheme up to $250,000 per account holder per institution.
How much do I need in my offset to make it worthwhile?
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It depends on the fees. If your loan has a $395 annual package fee and a 6% rate, you need about $6,583 sitting there permanently just to break even on the fee ($395 divided by 6%). Beyond that, every extra dollar saves you money. If you can keep your salary, emergency fund and short-term savings there, the maths usually works, especially on larger loans.
Can I have multiple offset accounts?
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Some lenders allow multiple offset accounts linked to one loan, which lets you separate savings goals (say an emergency fund and a holiday fund) while all balances offset the same loan. Not all lenders offer it, so check before you apply.
Is an offset account better than making extra repayments?
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For owner-occupiers the financial outcome is similar, but the offset keeps your money accessible, which is a real advantage. For property investors the offset is generally better because it preserves the deductible loan balance. If easy access tempts you to spend, extra repayments (with redraw used only when truly needed) can be a better behavioural choice.
Keep reading
Books worth reading
📚 Recommended reading
The Barefoot Investor
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The Barefoot Investor
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Australia's best-selling money book ever. A simple system for accounts, budgeting, debt and a real emergency fund in one.
Making Money Made Simple
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Making Money Made Simple
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Australia's classic, comprehensive money guide covering tax, super and investing, updated for today.
The Armchair Guide to Property Investing
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Two of Australia's most trusted property voices lay out a plain-English roadmap to building a portfolio on an average income. Practical, local, and refreshingly free of get-rich-quick hype.
Some links above are affiliate links. If you buy through them, Snowball Invest may earn a small commission at no extra cost to you. We only recommend books we'd suggest anyway.
Sources
- ASIC Moneysmart, mortgage offset accounts
- ASIC Moneysmart, home loans
- ATO, interest expenses on rental properties
General information only, not personal financial or tax advice. Tax rules change and circumstances vary. Consider a licensed mortgage broker, financial adviser, or registered tax agent before acting.
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General information only. This article is educational and does not constitute personal financial advice. It does not account for your circumstances. Consider your own situation and seek advice from a licensed adviser before acting. Read our full disclaimer.
Timothy Hirou Gaschereau
Founder of Snowball Invest, not a financial adviser.
I write about what I'm learning myself, because nobody ever taught us how to take control of our own money. It's a skill, not a mystery, and it's never too late to learn it. The best day to start was yesterday, the second best is today.
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