Offset accounts explained: how they work, what they save, and when they don't (2026)

What an offset account actually is

An offset account is a transaction account linked to your home loan. It works like any everyday account: you can deposit salary, pay bills, use a debit card, transfer money. The difference is that the balance in the account is subtracted from your loan principal each day when interest is calculated.

If your loan is $600,000 and you have $50,000 in the offset account, interest is calculated on $550,000 of principal that day. The bigger the offset balance, the lower the daily interest charge. Loan term and minimum repayment stay the same; the principal portion of each repayment just goes up because less of the repayment is interest.

How it saves you interest (the maths)

Interest on Australian home loans is typically calculated daily and charged monthly. Each day, the lender takes the loan balance, subtracts the offset balance, multiplies by the daily interest rate, and adds that to the month’s interest tally.

Worked example. $600,000 loan, 6.5 per cent rate, $50,000 average offset balance over the year.

• Without offset: interest on $600,000 at 6.5% = $39,000/year
• With $50K offset: interest on $550,000 at 6.5% = $35,750/year
• Saving: $3,250/year, every year the offset balance stays at $50,000

That saving compounds. A $50,000 average offset balance held for 20 years saves $65,000 in total interest, ignoring the knock-on effect of the loan paying down faster (because more of each repayment goes to principal). Real total saving over 20 years on a 25-year loan: closer to $85,000 to $95,000.

Offset vs redraw: which to use when

Redraw is the cheaper cousin of offset. It’s a feature on the loan itself: any extra repayments you make above the minimum can be pulled back out (redrawn) later. Interest is calculated on the lower balance after the extra repayment, which gives you the same interest-saving effect as offset.

Three differences matter:

• Status of the money.Offset balance is your money in an account. Redraw is a repayment you’ve made that the lender allows you to reverse. For most owner-occupier purposes that distinction doesn’t matter; it matters a lot for investment loans (see below).
• Cost.Offset is almost always part of a packaged loan with an annual fee ($250 to $400). Redraw is often included for free on basic-rate variable loans. If you don’t need offset specifically, a basic loan with redraw can save you the package fee.
• Friction. Offset money is in a transaction account with a debit card. Redraw money has to be requested from the lender (some are instant; some take 1 to 3 days). Offset is more usable as an emergency fund.

Offset vs a high-interest savings account

High-interest savings accounts (HISAs) in 2026 typically offer 4 to 4.75 per cent on balances up to $250,000, conditional on monthly deposit and withdrawal rules. Sounds competitive with a 6.5 per cent loan saving. It isn’t, once you tax it.

HISA interest is fully taxable as ordinary income. On a 32.5 per cent marginal rate, 4.5 per cent gross becomes 3.04 per cent after tax. On a 37 per cent marginal rate, 2.84 per cent after tax. On a 47 per cent marginal rate (including Medicare), 2.39 per cent after tax.

Offset interest savings, by contrast, are not taxable. You didn’t earn income; you avoided expense. Every dollar of interest saved is a dollar in your pocket, untaxed. On a 6.5 per cent loan, offset effectively earns you 6.5 per cent after-tax. The HISA cannot match this.

Rule: any cash you’d otherwise hold in a savings or chequing account should sit in the offset.

Is the package fee worth it?

Offset accounts almost always sit inside a packaged home loan, which carries an annual fee of $250 to $400. The package usually includes a rate discount (10 to 25 basis points), the offset feature, free credit card, fee waivers on other products. Whether it’s worth it depends on whether your average offset balance saves more interest than the fee costs.

Breakeven calculation. Annual fee ÷ loan rate = minimum average offset balance required.

• $400 fee ÷ 6.5% = $6,154 average balance to break even
• $300 fee ÷ 6.5% = $4,615 average balance to break even
• $250 fee ÷ 6.5% = $3,846 average balance to break even

Below that average balance, you’re paying more in fees than you’re saving in interest. Above it, the offset pays for itself (and the rate discount on top is pure upside). For most households with a salary running through the account, average balance is comfortably above $10,000, so the package works. For low-balance situations (early career, fresh deposit, all cash spent), a basic-rate loan without the package is sometimes the cheaper option.

Why offset matters more on investment loans

Investment-loan interest is tax-deductible against rental income (and other income, in the case of negative gearing). Owner-occupier loan interest isn’t deductible. That difference changes how offset and redraw work tactically.

Here’s the trap. If you use redraw on an investment loan, the ATO can re-classify a portion of the loan as non-deductible based on what you spent the redrawn money on. Example: $400,000 investment loan, you redraw $20,000 to buy a car. Even after you pay the $20,000 back via extra repayments, the ATO treats the loan as having two parts: $380,000 deductible (rental-related) and $20,000 non-deductible (car-related). The car-related portion stays non-deductible for the life of the loan.

Offset doesn’t have this problem. Money in an offset account is your money, not a loan repayment. Pulling it out and spending it on a car doesn’t affect the loan’s deductibility at all. For investment loans specifically: never use redraw, always use offset.

See our negative gearing guide for the full deductibility framework.

Using offset to build your next deposit

When you upgrade your owner-occupier home or buy an investment property, the cleanest deposit you can produce is your offset balance. It’s already yours, already accessible, and pulling it out doesn’t trigger any tax event.

The mechanics:

1. You hold $80,000 in the offset of your owner-occupier loan.
2. You buy an investment property. You withdraw the $80,000 from offset and use it as the deposit.
3. The offset balance drops to $0. Your owner-occupier loan now charges interest on the full balance again (still owner-occupier, still non-deductible).
4. The new investment loan is sized at $560,000 (property price minus $80,000 deposit). All of the investment loan’s interest is tax-deductible.

This is cleaner than the alternative (refinancing your owner-occupier loan to extract equity, then re-borrowing it as an investment loan) because there’s no debt re-classification needed and no refinance friction.

Common mistakes that cost real money

• Holding cash in a separate savings account. Even at 4.5 per cent gross HISA, the after-tax return is lower than the offset saving on any loan above 4 per cent.
• Using redraw on an investment loan.Will cost you tax deductions you can’t get back.
• Paying the package fee on a low-balance offset. Run the breakeven number. If your average balance is below it, switch to a basic variable loan.
• Not negotiating the package fee waiver. Most lenders will waive the fee for the first year, sometimes longer, as a competitive lever. Ask. If they say no, your broker can usually get it.
• Splitting cash across multiple banks. Cash held outside your offset is cash earning less than it could. Consolidate.
• Forgetting to use offset during interest-only periods. On interest-only investment loans the offset saving is the entire game. Maximising the offset balance is the only way to reduce the interest bill during the interest-only period.
• Using offset for sinking funds and forgetting they’re there. Annual insurance, rates, holidays: sitting in offset, all good. Withdraw at bill time, pay the bill, then actually replenish. The benefit only persists if the balance persists.

When an offset account isn’t worth it

Three situations where offset doesn’t earn its keep:

• Tiny balances.If your offset average sits below the package-fee breakeven (typically under $5,000), you’re paying more in fees than you’re saving in interest. Switch to a basic variable loan.
• Fixed-rate loans.Most fixed-rate loans don’t allow offset at all, or only allow it on a portion of the loan (10 to 50 per cent of the fixed balance). If you’ve fixed everything, offset isn’t available anyway. See the fixed vs variable guide for the trade-off.
• You actively pay down the loan.If your strategy is to make extra repayments and never withdraw them, redraw on a basic-rate loan gives you the same interest saving without the package fee. The offset advantage is the access, and you’ve said you don’t need access.