How to Check Your Offset Account Is Linked and Working

Short answer

Check three things: the offset account exists, it is linked to the intended home-loan account or split, and the lender is applying an interest benefit.

Start in online banking, then ask the lender for written confirmation if the link is not clear. Recheck after refinancing, changing products or restructuring loan splits.

A rough interest calculation can identify a figure worth querying, but it cannot prove a bank error. Daily balances, transaction timing, rates, fees, rounding and partial-offset rules can all change the statement amount.

Why this check matters

ASIC reported on 29 July 2026 that eight reviewed banks had paid more than $55 million in customer compensation for offset-account failures reported between September 2023 and August 2025.

The review covered banks representing more than 70% of Australia's $2.5 trillion home-loan market and examined data for 204,000 unique loans. ASIC said the full extent of failures could not be estimated reliably because bank records and data quality varied.

Among failures identified by banks in the review data:

These figures describe the reviewed data. They do not mean 55% of all Australian offset accounts are unlinked.

Check 1: confirm the account exists

Look for the offset account in the lender's app or online banking. Match the account number with the loan offer, settlement letter or product documents.

If the loan package promised an offset account but no transaction account appears, contact the lender. Keep the application, broker email, product schedule and settlement correspondence that records what was requested.

Check 2: confirm the correct loan link

One offset account may link to one variable split, while another split may be fixed or ineligible. Do not assume a transaction account offsets every loan shown under the same customer profile.

Ask the lender to confirm in writing:

• the offset account number;
• the linked loan account or split;
• whether it is a 100% or partial offset;
• the date the link started; and
• whether a refinance or product change requires relinking.

This is especially important after settlement, refinancing, changing repayment products or creating new fixed and variable splits.

Check 3: look for the interest benefit

ASIC Moneysmart says most home-loan interest is calculated daily. For a full offset, the lender generally subtracts the recognised offset balance from the linked loan balance before calculating that day's interest.

A rough daily check is:

Indicative daily interest = (loan balance minus eligible offset balance) x annual rate / day-count basis

Suppose the linked loan balance is $600,000, the eligible offset balance stays at $50,000, the rate is 6.20% and a 365-day basis is used.

• Without the offset: about $101.92 interest for the day.
• With the offset: about $93.42.
• Indicative difference: about $8.49 for that day.

This is a sense check only. A lender may use end-of-day balances, transaction cut-offs, a leap-year basis, rate changes, product-specific rounding or a partial offset. Monthly statements can also span different numbers of days.

Read How Home Loan Interest Is Calculated Daily before comparing a statement line with a simple calculation.

A practical statement check

Use a period where balances and rates were relatively stable.

1. Record the loan balance, offset balance and annual rate for each day if available.
2. Confirm the offset was linked for the whole period.
3. Note deposits or withdrawals near the lender's daily cut-off.
4. Estimate the daily interest on the net recognised balance.
5. Add the daily estimates for the statement period.
6. Compare the total with the interest charged, allowing for the lender's stated method.

If the difference remains material, ask the lender for its daily interest calculation and the effective link date. Do not assume the scheduled repayment itself will fall when the offset works. Often the repayment stays the same and more of it reduces principal.

What to do if something looks wrong

Contact the lender first and make the issue specific. Include the offset and loan account numbers, the date range, the expected link, relevant documents and the interest difference you want explained.

Ask for:

• written confirmation of the link and effective date;
• the lender's calculation for the disputed period;
• correction of any setup or linking error; and
• an assessment of interest remediation if the lender confirms a failure.

Keep screenshots, statements, application records and complaint reference numbers. If the lender's internal complaints process does not resolve the issue, the Australian Financial Complaints Authority explains how eligible credit and home-loan complaints can be lodged.

What this check cannot establish

This guide cannot determine that a lender breached a contract, calculated interest incorrectly or owes compensation. It also cannot confirm that an offset product is suitable or better value than a basic loan.

Use the Offset Account Break-Even Calculator to compare an average balance with an annual fee and rate premium. That tool estimates product economics, while this guide checks whether the operational link appears to exist.

Related calculators and guides

• Offset Account Break-Even Calculator
• Extra Repayments and Offset Calculator
• Loan Comparison Calculator
• Offset Account vs Redraw
• How Home Loan Interest Is Calculated Daily

Sources

• ASIC: Hidden mortgage offset failures costing Australians millions, published 29 July 2026 and checked 7 August 2026.
• ASIC Moneysmart: Mortgage offset accounts, updated 28 July 2026 and checked 7 August 2026.
• Australian Financial Complaints Authority: Credit, finance and loan complaints, checked 7 August 2026.

General information disclaimer

This check is indicative only and cannot establish that a lender calculated interest incorrectly. Daily balances, transaction cut-offs, rate changes, partial-offset rules, fees, rounding and loan terms can affect the result. Ask the lender for its calculation and written confirmation of the account link. This is general information, not credit, financial or legal advice.

Last updated: 7 August 2026.