What Is a Notice of Assessment?
A Notice of Assessment (NOA) is an official document the Australian Taxation Office issues after processing your income tax return. It is the ATO's formal calculation of your tax position for the financial year, showing exactly how much tax you owe, any credits you are entitled to, and whether you receive a refund or have an amount owing.
The NOA is issued for every tax return lodged, whether you lodge through myTax, a registered tax agent, or on paper. It is typically available within 2 weeks of electronic lodgement; for paper returns the ATO says most refunds issue within 50 business days.
Your NOA is an important document. You may need it when applying for loans, government benefits, or rental applications as proof of income. Keep a copy of each year's NOA for at least 5 years (the standard ATO record-keeping period). You can access all your past NOAs through your myGov account linked to the ATO.
How to Read Your Notice of Assessment
Your NOA follows a structured calculation. Each line builds on the previous one to arrive at your final refund or debt. Here's what each section means:
| Line Item | What It Means | Example ($90K salary, 2025-26 return) |
|---|---|---|
| Taxable Income | Your gross income minus allowable deductions | $87,000 |
| Tax on Taxable Income | Income tax calculated using progressive tax brackets | $16,888 |
| Less: Tax Offsets | Reductions including LITO, private health rebate, etc. | −$325 |
| Plus: Medicare Levy | Standard 2% Medicare levy on taxable income | +$1,740 |
| Plus: Medicare Levy Surcharge | 1%–1.5% if no PHI and income over $101,000 (singles, 2025-26) | $0 |
| Plus: HECS-HELP Repayment | Compulsory repayment if income exceeds threshold | +$3,000 |
| Total Tax Liability | Sum of all taxes and levies | $21,303 |
| Less: PAYG Credits | Tax already withheld by your employer(s) during the year | −$23,500 |
| Result | Refund (if negative) or Amount Owing (if positive) | Refund: $2,197 |
Understanding Each Line
Taxable Income is your total assessable income (salary, wages, interest, dividends, capital gains, rental income) minus allowable deductions (work-related expenses, self-education, working from home, etc.). This is the starting point for your tax calculation.
Tax on Taxable Income is calculated using the progressive tax brackets. For a 2025-26 return, the first $18,200 is tax-free, $18,201–$45,000 is taxed at 16%, $45,001–$135,000 at 30%, and so on (the 16% rate fell to 15% from 1 July 2026, so your 2026-27 return will use 15%). The ATO applies each bracket sequentially to your taxable income.
Tax Offsets reduce the tax calculated above. The most common offset is the Low Income Tax Offset (LITO), which provides up to $700 and phases out completely at $66,667. Other offsets include the private health insurance rebate, senior and pensioner tax offset, and zone tax offset. Non-refundable offsets can reduce tax to zero but not below.
Medicare Levy is a flat 2% of your taxable income. No levy is payable at or below the low-income threshold ($28,011 for singles in 2025-26), and a reduced levy applies up to $35,013. See our Medicare Levy Guide for the full details, including exemptions for foreign residents and certain visa holders.
Medicare Levy Surcharge applies on a 2025-26 return if your income for MLS purposes is over $101,000 (singles) or $202,000 (families) and do not hold eligible private hospital cover. The surcharge is 1%–1.5% depending on your income tier. See our Private Health Insurance & Medicare guide.
HECS-HELP Repayment is your compulsory student loan repayment, calculated on your Repayment Income. Under the marginal system introduced for 2025-26, you only pay on income above the threshold: $67,000 on a 2025-26 return, rising to $69,528 for 2026-27. The amount shown on your NOA is the total compulsory repayment for the year.
PAYG Credits represent the tax your employer(s) withheld from your pay during the year. If your employer withheld more than your total tax liability, you receive a refund. If they withheld less, you owe the difference.
What to Do If You Disagree With Your NOA
If you believe your Notice of Assessment contains an error, you have two main options: requesting an amendment or lodging a formal objection.
Requesting an Amendment
For most individual taxpayers, you have 2 years from the date of your original assessment to request an amendment. If you are classified as having more complex tax affairs (e.g., you are a beneficiary of a trust or have a foreign income), the review period extends to 4 years.
You can request an amendment through:
- myTax: Log in to your myGov account, navigate to the ATO, and select “Amend my return”
- Tax agent: Your registered tax agent can lodge an amendment on your behalf
- Paper form: Complete a paper amendment request and mail it to the ATO
Common reasons for amendments include: forgetting to claim a deduction, incorrect income reported by a payer, or receiving a revised payment summary after lodging.
Lodging a Formal Objection
If the ATO has made a decision you disagree with (as opposed to a simple error), you can lodge a formal objection. Objections must be lodged within 2 years of the assessment date for individuals. The ATO will review your objection and issue a decision, typically within 60 days.
If your objection is disallowed, you can escalate to the Administrative Review Tribunal (ART), which replaced the Administrative Appeals Tribunal on 14 October 2024, or the Federal Court for an independent review.
Important
Even if you lodge an objection, you are generally required to pay the assessed amount by the due date. If the objection is successful, the ATO will refund the overpayment with interest. If you are experiencing genuine financial hardship, you can request a deferral of payment.
Common NOA Scenarios
Why Did I Get a Tax Debt?
You receive a tax debt when your PAYG credits (tax withheld during the year) are less than your total tax liability. Common reasons include:
- Claiming the tax-free threshold at two jobs simultaneously
- Investment income (interest, dividends, rental) with no tax withheld
- Capital gains from selling shares or property
- Not declaring HECS-HELP debt to your employer
- Underpayment of Medicare Levy Surcharge
Why Is My Refund Different From Expected?
Common reasons your refund differs from your estimate include:
- ATO data matching: The ATO pre-fills income from banks, employers, and government agencies. If you missed reporting income, the ATO adds it automatically.
- Deductions disallowed: If the ATO does not accept a claimed deduction, your taxable income increases and your refund decreases.
- Prior year debt offset: The ATO may apply your refund to an outstanding debt from a previous year.
- Child support obligations: Refunds may be redirected to cover child support debts.
Use our Tax Return Calculator before lodging to estimate your expected outcome and identify any discrepancies early.
Frequently Asked Questions
About this guide▼
Information is sourced from the Australian Taxation Office's published guidance on Notices of Assessment, amendment processes, and objection procedures. The worked example uses the 2025-26 resident tax brackets, Medicare levy and HELP repayment rates, because that is the year covered by the notices being issued now. The worked example is illustrative and simplified. Individual NOA results depend on your specific income, deductions, offsets, and withholding arrangements.
Sources & References
- 1Notice of assessment, Australian Taxation Office
- 2Objecting to a decision, Australian Taxation Office
- 3Amending your tax return, Australian Taxation Office
- 4Individual income tax rates, Australian Taxation Office
Last verified: 9 October 2026. Our content is based on the latest information from official Australian government sources.
Anita Bell
AuthorFounder & Senior Bookkeeper
Accountancy degree (2015); certified in Xero, QuickBooks Online, MYOB, Saasu, Zoho and Reckon One
Anita Bell earned her accountancy degree in 2015 and has worked as a senior bookkeeper with Prime Bookkeeping for over 5 years. This built her skills in Australian and New Zealand tax legislation and industry regulations. She is certified in Xero, QuickBooks Online, MYOB, Saasu, Zoho and Reckon One, and works with payroll and rostering software including Gusto, Deputy, Tsheets and KeyPay. She has strong experience in hospitality, building and construction, financial services, real estate, ecommerce, and medical and health services.
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