Offset Account

An offset account is a transaction account linked to your variable-rate home loan. Each day, your lender subtracts the offset balance from the loan balance before calculating interest, so the money in the offset saves interest at your full mortgage rate. On an owner-occupied home the saving is tax-free, which makes it the highest guaranteed after-tax return most mortgage holders can get. A $50,000 offset balance on a $750,000 loan at 6 percent saves roughly $3,000 a year.

The offset-versus-redraw distinction is the part people blur. An offset is a separate account - your money, full access, interest savings only; a redraw facility is extra repayments sitting inside the loan, with the bank controlling access. On an investment property the distinction becomes tax: the offset preserves the loan balance and therefore the deductible interest, while redrawing for personal spending can contaminate the loan's deductibility. Not every loan offers an offset, and banks charge for the feature through higher rates or package fees.

Walk one month. You hold a $750,000 variable-rate loan at 6 percent with $50,000 sitting in the offset account. Interest is calculated daily: the lender charges on $700,000 rather than $750,000, which is roughly $115 a day instead of $123 - about $250 a month, or $3,000 a year, of interest you never pay. The saving is a direct function of the balance and how long it stays: the pay-cycle strategy - salary into the offset, everyday spending on a credit card paid in full by the due date - keeps the balance higher for longer.

The failure mode is the one worth knowing. A 2026 ASIC review found some banks failed to link or maintain offset accounts properly, so the money sat in the account while the interest was charged on the full loan balance - repayments stayed the same, so the harm was invisible. The review's example: a $750,000 loan at 6.25 percent with a $50,000 offset that was never linked cost over $3,000 in extra interest in one year and nearly $230,000 over the life of the loan. The offset account savings calculator shows what a working offset should be saving.

Checking is the two-minute habit. Confirm the offset is linked in your banking app or on the statement, re-check after any refinance or product switch - switching can break the link - and act quickly if the savings are not visible. The mortgage calculator prices the offset against the loan's rate and fees.

For an Australian reader, the offset account is where the emergency fund, the pay cycle and the mortgage meet. The after-tax arithmetic is the argument: interest saved on an owner-occupied home is not taxable income, so a 6 percent offset saving equals a 6 percent after-tax return. To match it in a savings account taxed at a 39 percent marginal rate you would need roughly a 9.8 percent headline rate, which no bank is paying. Compare the feature's cost against the interest it saves with the mortgage calculator, and check the offset-versus-redraw trade-off in the redraw facility entry. MoneySmart's guidance frames the offset as worth it when the loan is large, the balance is regular and flexibility matters.

A colleague named Brent (yes, that Brent) kept $40,000 in a savings account earning 4.5 percent while his offset sat empty. The savings interest was taxed down to roughly 2.7 percent net, while the empty offset meant he paid interest on the full loan balance. The money was in the wrong account, and the interest statement never said so. The highest-leverage thing most Australians can do is park the cash buffer in the offset rather than the savings account. Then verify the offset is actually linked - the 2026 ASIC review found banks failing at exactly that.