ATO objection time limits and late objections

The ATO objection time limit for an income tax assessment is generally 2 years after you are given the notice for most individuals and small or medium businesses, and 4 years for other taxpayers. GST and FBT assessments generally have 4 years, and most other decisions you can object to have 60 days (Taxation Administration Act 1953 (TAA), s 14ZW). If the time has passed, you can still lodge the objection with a written request asking the ATO to treat it as lodged on time.

We prepare ATO objections and late objection requests, often alongside the client's accountant, as part of our work on ATO audits and disputes. Section references are to the TAA unless we say otherwise.

ATO objection time limits: how long do you have to object?

The limit depends on the decision. The most common are:

Decision	Time limit	Law
Income tax assessment: most individuals, and small or medium businesses	2 years after the notice is given	s 14ZW(1)(aa)(i)
Income tax assessment: other taxpayers	4 years after the notice is given	s 14ZW(1)(aa)(ii)
GST assessment, including the net amount on your BAS	4 years after the notice is given	s 14ZW(1)(bg); Sch 1 s 155-35(2)
FBT assessment	4 years after the notice is given	s 14ZW(1)(aaa)
Amended income tax, GST or FBT assessment	The later of 60 days after notice of the amendment, or the period for the original assessment	s 14ZW(1B), (1BA)
Administrative penalty for a false or misleading statement, shortfall or scheme (Sch 1 Div 284)	60 days, or longer if you have longer to object to the assessment the penalty relates to	Sch 1 s 298-30(2); s 14ZW(1)(c), (1BB)
Refusal to remit a penalty, where more than 2 penalty units remain	60 days after notice of the decision	Sch 1 s 298-20(3); s 14ZW(1)(c)
Refusal to remit shortfall interest charge, where the charge not remitted is more than 20% of the extra tax	60 days after notice of the decision	Sch 1 s 280-170; s 14ZW(1)(c)
Super guarantee charge assessment	60 days after notice of the assessment	s 14ZW(1)(c); Superannuation Guarantee (Administration) Act 1992 s 42
Income tax private ruling	The later of 60 days after the ruling is made, or 2 or 4 years after the last day for lodging that year's return	s 14ZW(1A)
Most other objectable decisions	60 days after notice of the decision is served	s 14ZW(1)(c)

The ATO's guidance "What you can object to, and the time limits" (last updated 3 July 2026) covers less common decisions. Some have no objection right at all, such as a refusal to remit general interest charge under s 8AAG. For rulings, see ATO private rulings and objecting to them.

Who has 2 years and who has 4?

For income tax, you have 2 years if item 1, 2, 3 or 3A of the amendment table in section 170(1) of the Income Tax Assessment Act 1936 (ITAA 1936) applies to your assessment (s 14ZW(1)(aa)). Broadly, that covers individuals (subject to the exceptions below), and companies and trustees of trusts that are small or medium business entities for the year.

A small business entity carries on a business and generally has aggregated turnover under $10 million. A medium business entity is one under $50 million that isn't a small business entity (Income Tax Assessment Act 1997 (ITAA 1997) s 328-110; ITAA 1936 s 170(14)). For medium businesses, the 2-year limit applies for income years starting on or after 1 July 2021 (Treasury Laws Amendment (A Tax Plan for the COVID-19 Economic Recovery) Act 2020, Sch 3 item 40(6)), as the same ATO guidance also says. Earlier years stay on 4 years.

An individual generally has 4 years instead if, in that year (ITAA 1936 s 170(1), items 1 and 4):

• they carried on a business and weren't a small or medium business entity,
• they were a partner in a partnership that carried on a business and wasn't a small or medium business entity,
• they were a beneficiary of a trust that wasn't a small or medium business entity (with a limited exception for some self-assessing trusts), or
• it is reasonable to conclude a scheme was entered into for the sole or dominant purpose of getting them a tax benefit.

The trust exception catches many people. A trust that doesn't carry on a business, such as a family investment trust, can't be a small business entity, so its individual beneficiaries usually have 4 years. Similar exceptions apply to companies and trustees. Companies and trusts that aren't small or medium business entities, and super funds, generally have 4 years.

One trap: for assessments issued after 1 January 2025 for income years starting on or after 1 July 2024, a small or medium business can apply to have an assessment amended within 4 years (ITAA 1936 s 170(1) item 3A), but its objection period stays at 2 years (s 14ZW(1)(aa)(i)). The same periods largely decide how far back the ATO can audit you.

When does the objection period start?

The clock starts when the notice is given to you, not when you open it.

• Posted notices. The ATO's guidance says a notice given to you or your representative through Australia Post is currently treated as given 7 business days after it was issued.
• Companies and super funds. These self-assess: where no assessment has already been made for the year, lodging the return is treated as the ATO making the assessment and serving notice of it that day (ITAA 1936 s 166A(3)).
• GST. Lodging your GST return (usually your activity statement) is treated as notice of an assessment of the net amount, given that day (Sch 1 s 155-15).
• Assessments amended more than once. Where the 4-year period applies, it runs from the notice of the first assessment for that year (s 14ZW(1C)).

If you aren't sure when a notice was given, work from the earliest likely date, usually the issue date printed on it.

Once a deadline passes, a late objection depends on the ATO (or, on review, the Administrative Review Tribunal (ART)) agreeing to accept it.

How long do you have to object to an amended assessment?

When the ATO amends an assessment, for example after an audit, your objection is limited to the changes made and matters relating to them (s 14ZV). You can't use it to reopen parts of the return the ATO didn't change, although while the original amendment period is open, those parts can usually still be raised in an amendment request (ITAA 1936 s 170). The time limit is the later of 60 days after notice of the amended assessment, or the period for the original assessment (s 14ZW(1B) and (1BA)).

For example, suppose a company that isn't a small or medium business lodged its return in January 2023, and in mid-December 2026 an audit leads the ATO to deny a $200,000 deduction. The original 4-year period ends in January 2027, but 60 days from the amended notice runs into February 2027, so the February date applies. The objection can only challenge the denied deduction.

If a shortfall penalty came with the amendment, the penalty objection generally gets the same time, where that is longer than 60 days (s 14ZW(1BB)). We usually object to both together. See ATO penalties and penalty remission.

Can you lodge an objection out of time?

Yes. You lodge the objection together with a written request asking the ATO to deal with it as if it had been lodged on time (s 14ZW(2)). The request must state fully and in detail the circumstances of, and reasons for, the late lodgement (s 14ZW(3)).

The ATO must decide whether to agree and give you written notice (s 14ZX(1) and (2)). If it agrees, the objection is treated as lodged on time and decided normally (s 14ZX(3), s 14ZY).

The ATO's practice statement on late objections, PS LA 2003/7 (updated 2 April 2026), adds three practical points:

• Send the objection with the request. The ATO can't consider a request until it has the objection itself (para 7).
• A thin explanation isn't automatically fatal. ATO officers should give you a chance to improve it (para 6), but a full explanation the first time is far better.
• Inside the amendment period. A late objection without a request may be treated as an amendment request if the ATO can still amend and the claim is reasonable and likely to be allowed in full (para 8). Otherwise a request is needed (para 9), so we always include one.

What does the ATO consider for a late objection?

Under PS LA 2003/7, the ATO weighs all relevant factors (para 10), including:

• whether you lodged as soon as circumstances allowed,
• your explanation, and the length of the delay (years need a better explanation than days),
• whether you told the ATO you disagreed and took steps to contest the decision,
• whether you have an arguable case (without a full investigation of the merits), and
• whether the delay prejudices the ATO, for example through lost documents or witnesses.

When the ATO would generally agree

If nothing else counts against you, the ATO would generally agree where, for example (para 11):

• you were too ill to object,
• you didn't receive the decision because it went to the wrong address or the mail failed,
• incorrect ATO information led you to think objecting was futile,
• the ATO caused the delay,
• an adviser was negligent and failed to act on prompt instructions,
• the case raises an important question of law or practice, or
• you faced vulnerability such as family violence, financial coercion, homelessness or severe mental health struggles.

Most usefully, it would also generally agree where an individual or small business with a 2-year limit lodges, within 4 years, an objection that shows an arguable case. Each case is still decided on its own merits.

When it usually won't

The ATO would normally refuse (para 12) where, for example, the only explanation is a change of adviser, the delay is excessively long and unexplained, an extension would reopen a settled matter, or not objecting was your own decision despite having advisers.

What the courts have said

The main case, cited in PS LA 2003/7, is Brown v Commissioner of Taxation [1999] FCA 563, upheld by the Full Federal Court ([1999] FCA 1198). Hill J held that a taxpayer seeking more time generally only needs to point to facts giving an arguable case, a low threshold, and that the tribunal (then the AAT, since replaced by the ART) erred in law by trying the merits at that stage (paras 24–30, 56). Having to refund tax that may have been wrongly assessed is not prejudice to the Commissioner (para 52).

What if the ATO refuses your late objection?

You can apply to the ART to review the refusal (s 14ZX(4)). ATO officers are told to record the factors they considered and how they weighed them (PS LA 2003/7 para 14), which helps in preparing the review.

Apply promptly. The TAA sets 60 days for ART review of objection decisions (s 14ZZC(1)), but it sets no period for review of a refusal, and it switches off the ART's general time limit for these decisions (s 14ZZB(2)). Instead, the ART must dismiss an application it considers wasn't made within a reasonable time after the refusal, unless there are special circumstances (Administrative Review Tribunal Act 2024 (ART Act), s 20). There is no fixed deadline and little guidance on what counts as a reasonable time, so apply as soon as you can and, to be safe, within 28 days after you are given the refusal notice. If that time has already passed, still apply straight away and explain the delay.

What are the deadlines after an objection decision?

Once the ATO decides the objection, you generally have 60 days after being served with notice of the decision to apply to the ART (s 14ZZC(1)) or appeal to the Federal Court (s 14ZZN). The ART can extend its time, even after it has expired, if that is reasonable in all the circumstances (ART Act, s 19), but don't plan on it.

In both, you are limited to the grounds in your objection unless the ART or the court orders otherwise (s 14ZZK, s 14ZZO), so thin grounds can cost you later. See how to write an ATO objection and challenging an objection decision in the ART and Federal Court.

If the ATO hasn't decided your objection within 60 days of lodging it (or of agreeing to accept it late, or of receiving information it asked for in writing within that time), you can give it written notice requiring a decision. If there is still no decision 60 days later, the objection is taken to be disallowed, and you can seek review or appeal (s 14ZYA).

What to do if your deadline is close or has passed

1. Find the date the notice was given, using the rules above.
2. If time remains, lodge a complete objection in the approved form, stating the grounds fully and in detail (s 14ZU).
3. If time has passed, lodge the objection and the request together. Explain every period of delay in a dated timeline, attach evidence such as medical letters, ATO correspondence or emails instructing an adviser, and show clearly arguable grounds. You don't need to prove the whole objection yet.
4. Deal with the debt. Objecting doesn't change when the tax is due, a pending ART review generally doesn't stop recovery (s 14ZZM), and interest generally keeps running. A payment arrangement can stop the debt becoming a second problem.

Next step

Send us every page of the notice you disagree with, any amended assessment, audit or position paper letters, and the dates you or your accountant received each one. If the deadline has passed, add a short note on why, with any evidence. In a first call we'll tell you which time limit applies, when it ends or ended, and whether a late objection request is worth making.