Objecting to an ATO decision: a practical guide

When a client disagrees with an assessment or another ATO decision, the formal route is an objection under Part IVC of the TAA 1953. It also opens the door to external review. In most cases you cannot go to the Administrative Review Tribunal or the Federal Court without first objecting and getting an objection decision.

This guide covers what can be objected to, the time limits and how they are counted, late objections, how to lodge and what to put in, what the ATO can decide, and the two external review paths. A deadline checker for the common cases sits near the end.

Objection or amendment request

Not every disagreement needs an objection. If the client simply left out a deduction or income, a request to amend the return may be simpler. An objection is the right tool when:

• the ATO has made a decision the client disagrees with, such as an amended assessment after an audit, a penalty or a private ruling
• the client may want external review later, because the grounds stated in the objection usually set the limits of any later review
• the amendment period is closing and a formal record of the dispute is needed

The ATO's own steps page suggests checking whether another dispute option suits better, and speaking to a registered tax professional, before objecting.

What can be objected to

Part IVC only applies where another provision says a person who is dissatisfied with a decision may object to it "in the manner set out in this Part". Section 175A of the ITAA 1936, for example, gives that right for income tax assessments. The ATO describes the objectable decisions in its list of time limits, which includes:

• income tax assessments and amended assessments, including tax offsets and study loan repayments
• decisions to retain refunds
• GST, fuel tax credit, wine equalisation tax and luxury car tax assessments and reviewable decisions
• FBT assessments
• excess contributions and transfer balance determinations and assessments
• super guarantee charge assessments (employers only; employees cannot object to an SG assessment)
• administrative penalties, and decisions not to remit penalties or shortfall interest above set limits
• private rulings
• ABN decisions, excise decisions and some STP decisions

Limits on what can be objected to

• Nil assessments. Under s 175A(2) of the ITAA 1936 a taxpayer cannot object to an assessment that says there is no taxable income, or that there is taxable income but no tax payable, unless the objection seeks an increase in the liability or in tax offset refunds.
• Amended assessments. Under s 14ZV, an objection to an amended assessment is limited to the alterations or additions made by the amendment, or matters relating to them. It does not reopen the whole return.
• Private rulings and later assessments. Under s 14ZVA, once there has been an objection to a private ruling, an objection to the assessment on the same matter is limited to grounds that were not, and could not have been, grounds of the ruling objection. The ATO also says you cannot object to a private ruling if you already have an assessment for the same period; object to the assessment instead.
• Shortfall interest. A decision not to remit shortfall interest can only be objected to if the interest is more than 20% of the shortfall. On a $2,000 shortfall, the ATO's example, only a charge of $401 or more can be objected to.

Time limits

Section 14ZW sets the time limits. Most periods run from the day notice of the decision is given or served. Under s 36 of the Acts Interpretation Act 1901, a period expressed to begin after a day does not include that day, and if the last day falls on a Saturday, Sunday or holiday, the thing may be done on the next day that is not.

On when notice is given, the ATO says the period generally starts when the assessment, notice or ruling was given to the taxpayer or their representative, and that for mail this is currently 7 business days from the date it was issued through Australia Post. Keep the issue date and the date of receipt on file.

Income tax assessments: 2 years or 4 years

Section 14ZW(1)(aa) ties the objection period for an income tax assessment to the amendment periods in the table in s 170(1) of the ITAA 1936:

s 170(1) item	Who it covers (in summary)	Objection period
1	Individuals, unless they carry on a business (or are a partner or beneficiary connected with a business) that is not a small or medium business entity, or another exclusion applies	2 years after notice
2	Companies that are small or medium business entities, subject to exclusions	2 years after notice
3	Trustees of trusts that are small or medium business entities, subject to exclusions	2 years after notice
3A	Small or medium business entities applying for an amendment after the 2 year period	2 years after notice
Any other case	Everyone else, for example larger businesses, and taxpayers excluded from items 1 to 3	4 years after notice

The exclusions from items 1 to 3 matter. They include a scheme entered into for the sole or dominant purpose of obtaining a tax benefit, and, for individuals and companies, being a beneficiary of a trust that is not a small or medium business entity (unless the trustee is a full self-assessment taxpayer). Those taxpayers fall into the 4 year group.

The ATO describes medium business entities as those with aggregated turnover of at least $10 million but less than $50 million, and says the 2 year period applies to them for income years starting on or after 1 July 2021.

Item 3A gives small and medium business entities 4 years to apply for an amendment, but it does not lengthen the objection period. Section 14ZW(1)(aa)(i) still gives 2 years when item 3A applies.

Amended assessments

For an amended assessment the period ends on the later of:

• 60 days after notice of the amended assessment was served, and
• 2 or 4 years (matching the group above) after notice of the original assessment was served.

These rules are in s 14ZW(1B) and (1BA). If the assessment has been amended more than once, the notice that counts is the first assessment for the year (s 14ZW(1C)). The same later-of rule applies to amended FBT assessments, with 4 years.

Other common periods

Decision	Time limit	Source
FBT assessment	4 years after notice	s 14ZW(1)(aaa)
Income tax private ruling	Later of 60 days after the ruling was made and 2 or 4 years after the last day allowed for lodging the return	s 14ZW(1A)
Administrative penalty assessment (Division 284) that relates to an assessment	60 days, or the objection period for that assessment if it is longer	s 14ZW(1)(c) and (1BB)
Excess non-concessional contributions determination	4 years from the assessment	ATO time limits page
Super guarantee charge assessment	60 days	ATO time limits page
GST assessment	4 years and one day from the assessment, as the ATO states it	ATO time limits page
Any decision without a specific period	60 days after notice was served	s 14ZW(1)(c)

Other periods exist for decisions to retain refunds, deceased estates, petroleum resource rent tax, Pillar Two, excise and super regulatory decisions. Check the notice of decision, which usually states the period, and the ATO's list.

When the ATO asks for information while it is deciding whether to retain a refund, the objection period for that decision is extended by the time taken to provide it.

Late objections

A missed deadline is not the end. Under s 14ZW(2), the objection can still be lodged with a written request asking the Commissioner to deal with it as if it had been lodged in time. Section 14ZW(3) says the request must state, fully and in detail, the circumstances of and the reasons for the failure to lodge on time.

The Commissioner must decide whether to agree or refuse and give written notice (s 14ZX(1) and (2)). If the request is agreed, the objection is treated as lodged in time. If it is refused, the taxpayer can apply to the Administrative Review Tribunal for review of the refusal (s 14ZX(4)).

In practice, explain the whole period of delay, attach evidence for the reasons given, and lodge the complete objection with the request rather than a placeholder, so the merits can be seen at the same time.

How to lodge

Section 14ZU sets three requirements. The objection must:

1. be in the approved form
2. be lodged with the Commissioner within the s 14ZW period
3. state, fully and in detail, the grounds relied on

An objection to the Commissioner's failure to make a private ruling must also attach a draft ruling.

Channels

• Tax agents can lodge for clients, and the ATO provides an objection form for tax professionals.
• Individuals can lodge through ATO online services or with the objection form for taxpayers.
• Businesses, including sole traders, can lodge through Online services for business using myID, or online services via myGov.
• Other authorised contacts cannot lodge online. They can use the paper form or a letter, with a signed declaration.

Online lodgement gives a receipt ID. Keep it with the file. There is no fee to lodge an objection.

What to include

The ATO asks for full contact details, full details of the decision including the year or period, and the reasons for the objection, supported with relevant information, arguments and documents. In practice a strong objection sets out:

• the decision objected to, with the notice date and reference
• each ground as a separate numbered point, linking facts to the provision relied on
• the outcome sought, including what the assessment should be
• the evidence for each fact, indexed and attached
• any authority relied on

The grounds matter beyond the objection. On review in the Tribunal or an appeal to the Federal Court, the taxpayer is limited to the grounds stated in the objection unless the Tribunal or court orders otherwise (s 14ZZK(a) and s 14ZZO(a)). Include every arguable ground at the start.

Paying while the dispute runs

Objecting does not change the due date. A pending review or appeal does not stop the ATO recovering the amount (s 14ZZM and s 14ZZR). The ATO says it usually does not pursue recovery of a disputed debt until the dispute is finalised, interest keeps accruing daily, and large businesses are expected to pay at least half the disputed amount, or arrange a 50:50 arrangement. If the outcome reduces the debt below what was paid, the ATO refunds the difference.

What the ATO decides

For an objection lodged in time (or treated as lodged in time), the Commissioner must decide to allow it wholly or in part, or to disallow it (s 14ZY(1)), and must serve written notice of the objection decision (s 14ZY(3)). The ATO says the notice includes the reasons for its decision, and an amended assessment where relevant. If money is owed back, it is refunded with any interest the taxpayer is entitled to.

If the ATO takes too long

Section 14ZYA lets the taxpayer force a decision. Once 60 days have passed since the objection was lodged (or since a late-lodgement request was agreed), or 60 days after the ATO receives information it asked for in writing within that first 60 days, the taxpayer can give written notice requiring a decision. If no decision is made within 60 days after that notice, the objection is taken to be disallowed, and the review and appeal rights below become available.

Individuals, small businesses and not-for-profits with a tax or super dispute can also ask the ATO for in-house facilitation.

External review

If the taxpayer is dissatisfied with the objection decision, s 14ZZ gives a choice: apply to the Tribunal for review, or appeal to the Federal Court. Some decisions (ineligible income tax remission decisions) can only go to the Federal Court.

Administrative Review Tribunal

The Administrative Review Tribunal (ART) replaced the Administrative Appeals Tribunal on 14 October 2024. The ATO confirms that cases before the AAT moved automatically to the ART and that the change did not alter the time for seeking review. The commencement date is confirmed in the commencement table of the Administrative Review Tribunal (Consequential and Transitional Provisions No. 1) Act 2024.

• Time limit. Within 60 days after being served with notice of the objection decision (s 14ZZC(1)). The ART can extend the time on application under s 19 of the ART Act.
• Form. In writing, with a statement of the reasons for the application (s 14ZZC(2) and (3)).
• Nature of review. A merits review. The ATO describes the ART as able to confirm, vary or set aside a decision, or make a new one.
• Privacy. The hearing is held in private if the applicant asks (s 14ZZE).
• Documents. The ATO must give the ART its reasons, the notice, the objection, the objection decision and other relevant documents within 28 days after being notified of the application (s 14ZZF(2)).
• Burden of proof. The applicant must prove the assessment is excessive or otherwise incorrect and what it should have been, or for other decisions, that it should not have been made or should have been made differently (s 14ZZK(b)).

Small business taxation assessment decisions

Part IVC has special rules where the objection decision relates to a small business taxation assessment decision: an assessment of tax-related liabilities relating wholly or partly to carrying on a business, made in relation to a small business entity (s 14ZQ). For those decisions only:

• the ART can make an order staying or otherwise affecting the operation of the decision while it is reviewed (s 14ZZB(6) and s 14ZZM(2)), which for other tax decisions it cannot
• the order can include directing the ATO not to sue to recover the amount, to accept payment by instalments, or not to issue garnishee notices to third parties
• the applicant must satisfy the ART that the application and the request are not frivolous, vexatious, misconceived, lacking in substance or intended to unduly impede the administration of a tax law (s 14ZZH)

An order that would permanently change the decision, such as deferring when a liability is due or remitting interest, is not a stay order. The ATO's small business litigation funding program ended on 30 September 2025.

Federal Court

• Time limit. An appeal must be lodged within 60 days after the person is served with notice of the objection decision (s 14ZZN).
• Grounds and burden. The same limits as in the ART apply: the objection grounds, unless the court orders otherwise, and the burden of proving the assessment is excessive (s 14ZZO).
• Orders. The court can make any order it thinks fit, including confirming or varying the decision (s 14ZZP). An appeal on an ITAA 1936 decision can be transferred to the Federal Circuit and Family Court of Australia (Division 1) (s 14ZZS).

The ART suits most fact-heavy disputes because it reviews the merits afresh. The Federal Court suits disputes that turn on a question of law. Costs, privacy and the chance of a precedent all differ, and that choice is worth legal advice.

Once a decision of the ART or a court becomes final, the Commissioner must take the action needed to give effect to it within 60 days, including amending the assessment (s 14ZZL and s 14ZZQ).

Objection deadline checker

The checker below covers income tax assessments (original and amended), FBT assessments (original and amended), income tax private rulings, administrative penalties, decisions with the default 60 day period, and the 60 day limits for the ART and the Federal Court.

How it counts:

• the period starts the day after the date you enter
• "60 days after" is 60 calendar days, and "2 years after" ends on the same date 2 years later (a 29 February start ends on 28 February where there is no 29 February, the earlier date)
• "later of" rules show both dates and use the later one
• if the last day is a weekend, it also shows the next Monday under s 36(2) of the Acts Interpretation Act 1901, but it does not check public holidays

Example: an amended assessment issued after a review is given on 1 September 2026. The original assessment for the year was given on 20 October 2024 and the client is in the 2 year group. The 2 year period ends on 20 October 2026, but 60 days after the amended notice is 31 October 2026, so the later date applies. 31 October 2026 is a Saturday, so s 36(2) allows lodgement on Monday 2 November 2026. Lodging by Friday 30 October avoids the question.

You choose the 2 year or 4 year group and enter the notice date. The checker does not decide which s 170(1) item applies, when notice was given, or whether the decision is objectable. It does not cover GST and other indirect tax, super and SG matters, retained refunds, deceased estates or specialised taxes. For a plain count of business days between two dates, use the business days calculator.

Objection checklist

Questions

How long do I have to object to an income tax assessment?

2 years after notice of the assessment if item 1, 2, 3 or 3A of s 170(1) of the ITAA 1936 applies, which covers most individuals and small and medium business entities. Otherwise 4 years (TAA 1953 s 14ZW(1)(aa)).

What is the time limit for an amended assessment?

The later of 60 days after notice of the amended assessment and 2 or 4 years after notice of the original assessment. The objection is limited to the changes made by the amendment.

Can I lodge an objection after the time limit?

Yes, with a written request asking the Commissioner to treat it as lodged in time, stating fully and in detail the circumstances and reasons for the delay. A refusal can be reviewed by the Administrative Review Tribunal.

When did the Administrative Review Tribunal replace the AAT?

On 14 October 2024. Cases before the AAT moved automatically to the ART, and the 60 day period to apply for review of an objection decision did not change.

What if the ATO does not decide my objection?

After 60 days you can give written notice requiring a decision. If none is made within 60 days of that notice, the objection is taken to be disallowed and you can seek review or appeal (s 14ZYA).

Do I have to pay the disputed tax while I object?

The due date does not change and interest accrues. The ATO says it usually does not pursue recovery of a disputed debt until the dispute is finalised; large businesses are expected to pay at least 50%.

Sources

• Taxation Administration Act 1953, Part IVC (compilation 27 August 2026), Federal Register of Legislation
• Income Tax Assessment Act 1936, ss 170 and 175A (compilation 1 October 2026), Federal Register of Legislation
• Acts Interpretation Act 1901, s 36 (compilation 28 March 2026), Federal Register of Legislation
• Administrative Review Tribunal (Consequential and Transitional Provisions No. 1) Act 2024, commencement table
• ATO, What you can object to, and the time limits
• ATO, Steps to lodge an objection
• ATO, Object to a decision (print whole section: what to include, lodging, how we manage your objection)
• ATO, How we manage your objection
• ATO, Seek an external review of ATO decisions