Your Notice of Assessment (NOA) is the ATO's official calculation of your tax for the year, issued after your return has been processed — not the same as the on-screen estimate you saw while lodging. Reading it line by line tells you exactly how the ATO arrived at your refund or bill, rather than just the final number.
What is a Notice of Assessment, exactly?
It's the formal document the ATO issues once your return has been processed, confirming your taxable income and the tax calculation the ATO has actually applied — as distinct from the estimate myTax showed you before you clicked lodge. You'll find it in your myGov inbox, usually as a PDF, alongside a brief summary. AusTax AI's clients often ask about this document long after their return has been lodged, usually when applying for a loan and needing official proof of income.
Line by line: what each section means
| Line item | What it means |
|---|---|
| Taxable income | Your income after all allowable deductions have been subtracted |
| Tax on taxable income | Gross tax calculated using the resident marginal rates for the year |
| Less: tax offsets | Offsets like the Low Income Tax Offset, applied to reduce tax payable (non-refundable — can't take tax below zero) |
| Medicare levy | Generally 2% of taxable income, unless an exemption applies |
| Medicare Levy Surcharge (if applicable) | Extra charge if you didn't hold adequate private hospital cover and your income exceeds the threshold |
| HECS-HELP compulsory repayment (if applicable) | Calculated on repayment income once above the FY2025-26 threshold |
| Less: PAYG credits | Tax already withheld by your employer(s) during the year |
| Amount owing / refund | The net result — what you owe the ATO, or what's due back to you |
Why doesn't this match the estimate I saw in myTax?
The estimate on-screen is calculated instantly from the data you'd entered up to that point; the NOA reflects the ATO's own processing, including any data-matching, corrections, or account offsets applied afterwards. Our guide on why your refund estimate differs from your NOA goes through the specific reasons this happens.
What if a figure on my NOA looks wrong?
Compare it against your own records first — your income statements, bank interest, and any deduction substantiation — rather than assuming the ATO's figure is the error. If it genuinely looks incorrect (a wrong offset applied, or income double-counted), you can lodge an amendment; our guide on how to amend a tax return in myTax covers that process. If your return is still showing as under review rather than issued, see our guide on what "under review" means and how long it takes instead — you won't have a final NOA to check yet. It's also worth remembering the NOA is issued after processing is genuinely complete, so a figure that looks wrong at first glance is more often explained by a data-matching correction than by an actual ATO mistake.
Quick checklist for reading your NOA
- Check the taxable income figure matches what you expected after deductions
- Confirm any Medicare levy or surcharge applied (or didn't) matches your actual circumstances
- Look for a HECS-HELP line if you have a study loan, and check it against the current repayment bands
- If the bottom line differs meaningfully from your on-screen estimate, look for an "amount applied to other debt" line before assuming an error
- Keep a copy of the NOA itself, not just the refund amount — it's the document you'll need for loan applications or if a figure needs revisiting later
AusTax AI's dashboard keeps your lodged figures alongside the ATO's assessment once it's issued, so you're comparing the two directly rather than trying to remember what you originally entered.
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*Disclaimer: This is general information only and does not constitute personal tax advice. Consult a registered tax agent for advice tailored to your specific situation. Always verify against the latest ATO guidelines at ato.gov.au.*
*This is general information only, not personal tax advice. If a specific figure on your Notice of Assessment looks incorrect, confirm it with the ATO or a Registered Tax Agent before taking further action.*