You open the mail and there it is: a notice from the ATO. Not a refund. Not a routine letter. An amended assessment. The numbers have changed. Usually upwards. Often significantly.
Your first question: what exactly is this, and what am I supposed to do about it?
Your second question, probably within the next ten seconds: can I challenge it, or do I just have to pay?
Amended assessments are one of the most common triggers for tax disputes in Australia. They arrive after audits, compliance reviews, data-matching exercises, or sometimes just because the ATO has taken a second look at something you did years ago. They can reshape your tax position, your cashflow, and your relationship with the regulator.
The pathway from “I’ve received an amended assessment” to “I know what to do next” isn’t always obvious. Most business owners and directors don’t deal with these often enough to have a clear playbook. Accountants can explain the numbers, but deciding whether to accept, negotiate, or dispute the assessment is a different kind of question. It’s partly technical, partly commercial, and partly about risk.
This article walks you through what an amended assessment actually is, why you might receive one, and how to approach the decision of whether to challenge it. It’s written for business owners, directors, CFOs, and advisors who need to understand the dispute pathway without wading through procedural guides or legislation.
If you’ve just received an amended assessment, you’re probably under time pressure. This is the framework to help you make the right call.
Key Takeaways
- An amended assessment changes your original tax position, it might correct an error, adjust a claim, or disallow something the ATO now disagrees with, often resulting in additional tax, interest, and sometimes penalties
- You have 60 days from the date of the amended assessment to lodge an objection, or until the end of the original objection period for that year, whichever is later (different rules apply for small businesses)
- Objecting isn’t just ticking a box, you need to set out your grounds fully, provide evidence, and address the ATO’s reasoning in detail, or your objection will likely fail
- You can challenge an assessment on the facts, the law, or both, but you need to know which issue you’re actually disputing and have the evidence or legal argument to back it up
- You don’t automatically have to pay while you dispute, but you need to consider paying under protest, negotiating a payment plan, or applying for a stay of recovery depending on your cashflow and risk appetite
- If the ATO rejects your objection, you can escalate to the Administrative Appeals Tribunal or Federal Court, but those forums require proper preparation, evidence, and often specialist litigation counsel, not just your accountant.
What Is an ATO Amended Assessment?
An amended assessment is exactly what it sounds like: the ATO has changed your original tax assessment for a particular year.
When you lodge your tax return, the ATO issues an assessment. That assessment sets out how much tax you owe (or are owed back). For most taxpayers, that’s the end of the story. The numbers are final unless something changes.
An amended assessment means something has changed.
The ATO might have found an error in your return. They might have audited you and disagreed with how you’ve treated certain income, deductions, or tax offsets. They might have received new information through data-matching with banks, third parties, or other government agencies. Or they might have simply taken a closer look at a transaction or structure and decided it doesn’t stack up under the tax law.
Whatever the reason, an amended assessment re-calculates your tax position. It can go up or down, but if you’re reading this, it’s probably gone up. Often significantly. And it usually comes with interest on the additional tax. Sometimes penalties.
The practical effect: your tax liability for that year has increased, and the ATO expects you to pay the difference.
An amended assessment doesn’t automatically mean the ATO thinks you’ve done something dishonest. It might just mean they’ve taken a different view on how the law applies to your facts. But the burden is now on you to challenge that view if you disagree.
Why You Might Receive an Amended Assessment
Amended assessments don’t arrive at random. They’re usually the result of something the ATO has identified through its compliance activities.
Here are the most common triggers for businesses and commercial taxpayers.
ATO audits and reviews
The ATO runs targeted audit programs across different industries, structures, and risk areas. If you’re selected for audit, the ATO will request documents, ask detailed questions, and review your tax positions. If they disagree with how you’ve treated something, an amended assessment follows.
Common audit focus areas include trust distributions, related-party transactions, shareholder loans, and deductions that look unusually large compared to industry benchmarks.
Data-matching and third-party information
The ATO receives data from banks, property settlement agents, share registries, and government agencies. If that data doesn’t match what’s in your tax return, the ATO will often issue an amended assessment adjusting your income or deductions to reflect what they think the correct position should be.
Example: your bank statements show deposits that exceed the income you’ve declared. The ATO assumes the difference is assessable income unless you can prove otherwise.
Trust distribution disputes (Section 100A)
One of the most common areas for amended assessments in recent years has been trust distributions, particularly where the ATO applies Section 100A. The ATO takes the view that certain distribution arrangements are reimbursement agreements designed to reduce tax, and disallows the distributions accordingly. The amended assessment re-characterises the income and often imposes significant penalties.
Division 7A issues (loans to shareholders and associates)
If your company has made loans or payments to shareholders or their associates without proper documentation or commercial terms, the ATO can treat those amounts as dividends under Division 7A. An amended assessment will include the deemed dividend in your assessable income, often with interest and penalties.
Research and development tax incentive adjustments
If you’ve claimed R&D tax offsets, the ATO might review your claim and decide that some of your expenditure doesn’t qualify. They’ll issue an amended assessment reducing the offset and clawing back the tax benefit you received.
Errors or omissions in your original return
Sometimes it’s simpler. You or your accountant made a mistake. The ATO picked it up. They’ve corrected it with an amended assessment. These are usually straightforward to resolve if the error is genuine and you can provide supporting documentation.
The key point: amended assessments are often the ATO’s way of saying “we think you got it wrong”. Whether they’re right depends on the facts, the law, and how well you can defend your original position.
If you receive an amended assessment, the first step is to understand why. Read the ATO’s explanation carefully. It will usually set out the reasons for the adjustment, the legal basis, and the amount of additional tax, interest, and penalties. That explanation is your roadmap for deciding whether to challenge it.
Your Time Limits and Options to Respond
When you receive an amended assessment, the clock starts immediately.
You have three broad options: accept it and pay, negotiate with the ATO, or lodge a formal objection. Each option has different time limits, risks, and practical consequences.
The objection deadline: 60 days (usually)
If you want to formally challenge the amended assessment, you need to lodge an objection within 60 days from the date of the notice. That’s 60 calendar days, not business days.
There’s a wrinkle. For amended assessments, the time limit is 60 days from the amended assessment or until the end of the original objection period for that income year, whichever is later.
What does that mean? If the original assessment for that year was issued two years ago, and the objection period for that original assessment was two or four years (depending on whether you’re a small business or not), and that period hasn’t expired, you still have until the end of that original period to object to the amended assessment.
In practice, for most amended assessments issued after an audit, the 60-day rule is what matters. But if you’re close to the line, check the original assessment date and do the calculation.
Small businesses (aggregated turnover under $10 million) have a two-year objection period for original assessments. Other taxpayers have four years. Those timeframes extend the objection window for amended assessments issued within those periods.
If you miss the deadline, you can apply for an extension of time. The ATO can grant an extension if you can show a reasonable explanation for the delay and it’s reasonable in the circumstances to allow the late objection. But don’t rely on getting an extension. The ATO has discretion, and they don’t always say yes.
Paying, negotiating, or disputing
Lodging an objection is the formal dispute pathway. But it’s not your only option.
You can choose to pay the amended assessment without objecting if you accept the ATO’s position or decide that fighting it isn’t worth the cost, time, or risk.
You can also try to negotiate with the ATO before lodging an objection. Sometimes a phone call or letter to the auditor or case officer can resolve the issue, particularly if there’s been a misunderstanding about the facts or you can provide additional evidence. Negotiation doesn’t stop the clock. If you can’t reach an agreement, you still need to lodge an objection within the 60-day window to preserve your dispute rights.
Or you can lodge a formal objection and take the matter through the ATO’s internal review process, with the option to escalate to the Administrative Appeals Tribunal or Federal Court if the ATO rejects your objection.
Each pathway has consequences for cashflow, timeline, and risk. We’ll unpack those in the next sections.
The 60-day deadline is strict. If you think you might want to challenge the amended assessment, lodge the objection within that window even if you’re still gathering evidence or exploring negotiation. You can always withdraw an objection later if you settle. But you can’t lodge one late without permission.
How to Decide Whether to Challenge an Amended Assessment
Not every amended assessment should be disputed. Some should be paid. Some should be negotiated. Some should be fought all the way to the Federal Court.
The question is: which category does yours fall into?
This is where most taxpayers and advisors get stuck. The decision isn’t purely technical. It’s a mix of law, facts, evidence, commercial risk, and cashflow. Here’s how to think through it.
Start with the ATO’s reasoning
Read the ATO’s notice and explanation carefully. What is the ATO actually saying?
Are they disputing the facts? (For example, they say a transaction happened differently to how you’ve described it, or they don’t accept your version of events.)
Are they disputing the law? (They accept your facts but say the tax law applies differently.)
Or are they disputing both?
If the ATO’s reasoning is clearly wrong on the facts and you have documents, emails, contracts, or other evidence that prove your version, you have a strong basis to object.
If the ATO’s reasoning involves a legal interpretation and you believe their view of the law is incorrect, you also have a basis to object, but you’ll need to engage with case law, legislation, and legal argument. That’s where tax disputes specialists come in.
If the ATO is right on both the facts and the law, objecting is unlikely to succeed. In that case, your best option might be to negotiate a payment plan or, if penalties have been imposed, argue for a reduction in penalties based on your conduct and circumstances.
Assess the size of the exposure
How much money are we talking about?
If the amended assessment is for $10,000 and the cost of disputing it properly (including legal and accounting fees) is $20,000, the commercial decision is usually straightforward. Pay it and move on, unless there’s a principle at stake or a broader risk (for example, the ATO is challenging a tax treatment you’ve used across multiple years or entities).
If the amended assessment is for $500,000, or $2 million, or more, the calculus changes. The cost of disputing it might still be high, but the cost of not disputing it could be higher, particularly if you believe you’re right.
You also need to factor in interest and penalties. Interest accrues on unpaid tax from the original due date. Penalties can range from 25% to 75% of the tax shortfall depending on the ATO’s view of your conduct. If the total exposure (tax, interest, penalties) is material to your business, that weighs in favour of challenging it if you have a reasonable argument.
Consider the strength of your evidence
Can you prove your position?
Tax disputes are won and lost on evidence. If you can show contemporaneous documents, agreements, board minutes, emails, or expert reports that support your version of the facts, your objection has a much better chance of succeeding.
If your evidence is weak, missing, or inconsistent, objecting becomes riskier. The ATO and, if it escalates, the Administrative Appeals Tribunal or Federal Court will assess your case based on what you can prove, not what you say happened.
Think through: what documents do you have? What documents do you wish you had? Can you reconstruct missing evidence, or is it gone?
If you can’t build a solid evidentiary case, you need to be realistic about your prospects.
Factor in the risk of escalation
What happens if you object and the ATO says no?
If the ATO disallows your objection, you can escalate to the Administrative Appeals Tribunal (for most decisions) or the Federal Court. Both options involve additional time, cost, and public exposure. AAT hearings are less formal than court, but they still require proper preparation, witness evidence, and legal argument. Federal Court litigation is a full merits or judicial review process depending on the type of challenge.
You need to assess: are you prepared to take this to the AAT or Federal Court if the objection fails? If not, lodging an objection might just delay the inevitable.
On the flip side, the ATO knows when taxpayers are serious about disputing a case. A well-prepared objection with strong evidence and legal argument can sometimes lead to the ATO reconsidering its position or proposing a settlement.
Think about the broader consequences
Does this amended assessment have implications beyond the immediate tax liability?
For example, if the ATO is challenging a tax treatment you’ve used across multiple years, entities, or related parties, the outcome of this dispute could affect future assessments or trigger further audits.
If the ATO’s position on a particular legal issue (like Section 100A or Division 7A) is one you fundamentally disagree with, and the issue is likely to recur, it might be worth fighting on principle even if the dollar amount in this case isn’t huge.
Conversely, if the issue is isolated to one year and one transaction, and the ATO’s position is defensible (even if you don’t love it), accepting the amended assessment might be the pragmatic choice.
You also need to think about reputational and relationship risks. Disputing an assessment can sometimes lead to increased ATO scrutiny in future years. It doesn’t mean you shouldn’t dispute it, but it’s a factor to weigh in your decision.
If you’re unsure whether to challenge an amended assessment, get independent advice early. Your accountant can help you assess the facts and numbers. A tax disputes lawyer can assess the legal argument and your prospects of success. The combination of both views is often what you need to make the right call.
Preparing and Lodging an Objection: What the ATO Expects to See
If you decide to challenge the amended assessment, you need to lodge a formal objection. This isn’t a matter of writing a one-page letter saying “I disagree”. The ATO has specific requirements, and if you don’t meet them, your objection can be rejected on procedural grounds before they even look at the substance.
Use the approved form
Objections must be lodged in the approved form. For most taxpayers, that means completing the ATO’s objection form, which is available on the ATO website. You can lodge it online through the ATO’s systems if you’re a registered tax agent, or you can submit it by post.
The form requires you to identify the assessment you’re objecting to, set out your grounds of objection, and provide supporting material.
Set out your grounds fully and in detail
This is the most important part.
The ATO requires you to state your grounds of objection “fully and in detail”. What does that mean in practice?
You need to explain:
- What you say the ATO got wrong. Be specific. Is it a factual error? A legal interpretation? A calculation mistake? Don’t just say “the assessment is incorrect”. Say why.
- What the correct position should be. What do you say the tax outcome should have been? What is your version of the facts or your interpretation of the law?
- Why your position is correct. This is where you set out your evidence, your legal reasoning, and your argument. Reference documents, contracts, emails, or other material that supports your case. If you’re relying on a legal interpretation, explain the relevant law and why it applies differently to how the ATO has applied it.
Think of the objection as your opening submission in a dispute. It’s your opportunity to set out your case in full. The ATO’s decision-maker will read your objection and decide whether to allow it, disallow it, or partially allow it. If you don’t give them enough information to understand your argument, they’ll likely disallow it.
Provide supporting evidence
Attach the documents that prove your position. Contracts, invoices, emails, board minutes, trust deeds, loan agreements, expert reports, whatever is relevant.
If you’re objecting on the basis that the ATO has misunderstood the facts, your evidence needs to show what actually happened.
If you’re objecting on the basis that the ATO has misapplied the law, you still need evidence to establish the facts. The law applies to facts, so you need both.
Make it easy for the ATO decision-maker to follow your argument. Number your attachments, cross-reference them in your written objection, and organise them logically.
Address the ATO’s reasoning directly
Don’t ignore the ATO’s explanation in the amended assessment. Engage with it.
If the ATO has said “we think this transaction is a sham”, you need to address why it’s not a sham.
If the ATO has said “we think Section 100A applies”, you need to explain why it doesn’t (or why their application of it is wrong).
If the ATO has said “you don’t have sufficient evidence for this deduction”, you need to provide that evidence or explain why the evidence you have is sufficient.
The objection is your chance to dismantle the ATO’s case and replace it with yours. Don’t waste it by just asserting your position without dealing with theirs.
Get the details right
Make sure you identify the correct assessment. The objection form will ask for the notice of assessment number, the tax year, and other identifying information. If you get this wrong, the objection might not be valid.
Check the lodgement deadline again before you submit. If you’re close to the 60-day mark, lodge it early. Don’t rely on last-minute lodgement.
If you’re lodging the objection yourself (not through a tax agent), make sure you sign it and provide all the required information.
A good objection is clear, detailed, and backed by evidence. It tells a story. It explains what happened, why the ATO’s version is wrong, and why your version is correct. If you can’t do that in the objection, you’re unlikely to convince the ATO later.
What Happens After You Object: ATO Review, AAT, and Federal Court
You’ve lodged your objection. Now what?
The process from here depends on how the ATO responds and whether you’re prepared to escalate if they say no.
The ATO’s internal review
Once you lodge an objection, it goes to an ATO decision-maker (usually someone who wasn’t involved in the original audit or assessment). That person reviews your objection, the evidence, and the ATO’s reasoning, and decides whether to allow the objection, disallow it, or partially allow it.
There’s no fixed timeline for this. The ATO aims to finalise objections within a reasonable period, but in practice it can take months or, in complex cases, more than a year.
If the ATO doesn’t make a decision within 60 days, you have the right to treat the objection as disallowed and escalate to the Administrative Appeals Tribunal or Federal Court. Whether you do that depends on your strategy. Sometimes it’s better to let the ATO take their time and give them a chance to reconsider. Sometimes it’s better to force a decision and move the matter forward.
If the ATO allows your objection in full, they’ll amend the assessment back to the original position (or to whatever position you argued for). You win.
If the ATO disallows your objection, you receive a notice of objection decision. That notice will explain why the ATO has rejected your grounds. You then have a choice: accept the decision and pay, or escalate to the next level.
If the ATO partially allows your objection, they might reduce the amended assessment but not back to where you say it should be. You can still escalate the remaining disputed amount.
Escalation to the Administrative Appeals Tribunal (AAT)
If the ATO disallows your objection (or you treat it as disallowed after 60 days), you can apply to the Administrative Appeals Tribunal for review of the decision.
The AAT is an independent tribunal that reviews government decisions. It’s less formal than a court, but it’s still a legal process. You’ll need to file an application, pay a filing fee, and prepare a case that includes evidence, witness statements, and legal submissions.
The AAT conducts a merits review. That means they look at the facts and the law afresh and decide what the correct outcome should be. They’re not just checking whether the ATO made a procedural error. They’re deciding whether the assessment is right or wrong.
AAT hearings can take months or years depending on the complexity of the case and the tribunal’s workload. You’ll usually need legal representation. The ATO will be represented by lawyers from the Australian Government Solicitor or private firms.
The AAT can affirm the ATO’s decision, vary it, or set it aside. If you win, the assessment is adjusted accordingly. If you lose, the assessment stands.
You can appeal an AAT decision to the Federal Court, but only on a question of law. You can’t appeal just because you disagree with the tribunal’s factual findings.
Escalation to the Federal Court
Alternatively, instead of going to the AAT, you can apply to the Federal Court for judicial review of the objection decision. Judicial review is a different process. The court doesn’t re-decide the facts. It checks whether the ATO made a legal error in reaching its decision.
You can also appeal an AAT decision to the Federal Court, as mentioned above.
Federal Court litigation is expensive, formal, and time-consuming. It’s usually reserved for cases involving significant amounts, important legal principles, or situations where the taxpayer believes the ATO has fundamentally misapplied the law.
If you’re considering Federal Court litigation, you need specialist tax disputes counsel from day one.
How long does all this take?
If you object, expect the ATO’s decision to take anywhere from a few months to over a year. If you escalate to the AAT, add another year or more. If you go to the Federal Court, add another year or more again.
Tax disputes are not fast. You need to plan for a long timeline and factor that into your cashflow, business planning, and stakeholder communication.
The objection is just the first step. Most taxpayers assume that if they lodge a solid objection, the ATO will back down. Sometimes they do. Often they don’t. If you’re serious about disputing the assessment, you need to be prepared for the possibility of AAT or Federal Court proceedings and the time and cost that involves.
Managing Payment, Cashflow, and Enforcement Risk During a Dispute
Here’s the hard truth: lodging an objection doesn’t automatically stop the ATO from pursuing payment.
The amended assessment creates a debt. The ATO can take recovery action to collect that debt even while your objection is being considered, unless you take steps to manage the payment issue.
This is one of the most stressful aspects of disputing an amended assessment. You’re fighting about whether you owe the money, but the ATO is treating it as already owed. How do you navigate that?
Option 1: Pay the full amount under protest
If you have the funds, you can pay the full amended assessment (including interest and penalties) and continue with your objection.
This is called paying under protest. You pay the debt to stop interest accruing and avoid enforcement action, but you preserve your right to dispute the assessment. If you win the objection or appeal, the ATO refunds the amount you paid, with interest.
Paying under protest is the safest option from a cashflow and enforcement perspective, but it requires significant cash reserves. For many businesses, particularly SMEs, paying a six- or seven-figure amended assessment upfront just isn’t feasible.
Option 2: Negotiate a payment arrangement
If you can’t pay the full amount, you can negotiate a payment plan with the ATO. The ATO will usually agree to a payment arrangement if you’re engaging constructively and making reasonable offers.
A payment arrangement doesn’t stop interest accruing on the unpaid balance, but it does stop the ATO from taking immediate enforcement action like garnishee notices or director penalty notices.
When you’re negotiating a payment plan, be realistic about what you can afford. The ATO will want to see cash flow forecasts, financial statements, and evidence that you can meet the proposed payment schedule. If you default on a payment arrangement, the ATO’s enforcement options come back on the table.
Option 3: Apply for a stay of recovery
If you’re objecting or appealing to the AAT or Federal Court, you can apply for a stay of recovery. A stay is a court or tribunal order that temporarily prevents the ATO from taking enforcement action while the dispute is being resolved.
The AAT and Federal Court both have the power to grant stays. The test is whether it’s in the interests of justice to prevent recovery action. Factors include the strength of your case, your ability to pay, the risk of enforcement action causing irreversible harm (like forcing your business into liquidation), and the ATO’s interest in collecting the debt.
Stays are not automatic. You need to apply for them and persuade the tribunal or court that a stay is appropriate. If granted, a stay usually comes with conditions, such as making partial payments or providing security.
If you’re at risk of enforcement action and you believe you have a strong case, applying for a stay should be part of your strategy from the outset.
Option 4: Do nothing (not recommended)
If you lodge an objection but don’t pay anything and don’t negotiate a payment arrangement or apply for a stay, the ATO can pursue enforcement action.
That can include issuing garnishee notices to your bank or debtors, issuing director penalty notices (if you’re a director of a company and the debt relates to company tax), or commencing legal proceedings to recover the debt.
In the worst-case scenario, enforcement action can lead to insolvency and liquidation.
Doing nothing is almost never the right strategy. If you’re objecting, you need a parallel plan for managing the payment issue.
The strategic question: when to pay, when to fight on payment
The decision of whether to pay under protest, negotiate a payment plan, or apply for a stay depends on:
- Your cashflow and ability to pay
- The strength of your objection or appeal
- The risk of enforcement action
- The timeline for resolving the dispute
If you have strong cashflow and a high-risk appetite, paying under protest removes the enforcement risk and lets you focus on the substantive dispute.
If you don’t have the cash, a payment plan is usually the pragmatic middle ground.
If enforcement action would cause serious harm to your business and you have a reasonable case, applying for a stay is the right move.
The worst outcome is being blindsided by enforcement action because you didn’t think through the payment strategy early.
Disputing the assessment and managing payment are two separate but connected issues. You need a plan for both. Don’t assume that lodging an objection will stop the ATO from chasing payment. It won’t.
When to Involve Specialist Disputes Counsel
Your accountant can prepare your tax return, help you understand the numbers, and often assist with objections on straightforward factual issues.
But there’s a point in most tax disputes where you need a different kind of advice. When you’re facing a material amended assessment, complex legal arguments, or the prospect of AAT or Federal Court proceedings, you need lawyers who specialise in tax disputes and commercial litigation.
Here are the signals that you’ve reached that point.
The ATO is disputing the law, not just the facts
If the amended assessment involves a legal interpretation of the tax legislation, case law, or ATO guidance, that’s a litigation issue. Your accountant can explain what the ATO thinks the law says, but assessing whether the ATO is right, building a legal argument, and running it through an objection or appeal requires legal expertise.
Examples: Section 100A trust distribution arguments, Part IVA general anti-avoidance provisions, transfer pricing disputes, Division 7A deemed dividend issues. These are all areas where the law is complex, contentious, and often unclear. You need lawyers who litigate tax cases.
The exposure is large enough to threaten your business
If the amended assessment (including interest and penalties) is large enough to materially impact your cashflow, balance sheet, or ability to operate, you need strategic advice on how to manage the dispute from a commercial and legal perspective.
This isn’t just about preparing an objection. It’s about understanding your options, assessing risk, managing payment and enforcement, and positioning the dispute for the best possible outcome.
You’re facing enforcement action or director penalties
If the ATO has issued garnishee notices, director penalty notices, or other recovery action, you’re in a litigation context. You need advice on your legal rights, defences, and options to stop or challenge the enforcement action.
The objection has been disallowed and you’re considering AAT or Federal Court
Once you’re past the objection stage, you’re in a formal dispute resolution process. The AAT and Federal Court are legal forums. You need legal representation, not accounting advice.
Even if your accountant has helped you through the objection, escalating to the tribunal or court requires a different skill set. Tax disputes lawyers know how to prepare applications, draft submissions, lead evidence, cross-examine ATO witnesses, and present legal arguments. That’s not what accountants do.
You need a second opinion on the ATO’s position
Sometimes it’s worth getting independent legal advice just to reality-check the situation. Your accountant might say “the ATO’s position is defensible” or “we think we can negotiate this”. A tax disputes lawyer can give you a cold, hard assessment of your prospects, the strength of your case, and whether fighting is worth it.
That advice is often the difference between making a good decision and an expensive mistake.
The issue affects multiple years or entities
If the ATO’s position on this amended assessment has implications for other income years, other group entities, or related parties, you need advice on the broader risk and how to manage it.
Tax disputes lawyers can help you assess the full exposure, coordinate responses across multiple entities, and structure a dispute strategy that protects your interests across the board.
The right time to involve tax disputes lawyers is before the objection deadline, not after the objection has been disallowed. Early advice lets you build the strongest possible case from day one and avoid procedural missteps that can’t be fixed later.
Common Scenarios: What to Do in the First Week
Let’s ground all of this in some practical scenarios. You’ve just received an amended assessment. What should you actually do in the first week?
Scenario 1: Trust distribution amended assessment (Section 100A)
You’re a trustee of a family trust. The ATO has issued an amended assessment disallowing distributions to adult children, re-characterising the income as assessable to the trust at the top marginal rate. The assessment includes significant additional tax and penalties.
What to do now:
Within 48 hours, brief your accountant and a tax disputes lawyer. Get copies of the trust deed, distribution minutes, loan agreements, and any documentation of how the funds were used. Start building the factual narrative: why were the distributions made? What was the commercial purpose? Were there reimbursement agreements (and if so, what did they actually say)?
Check the objection deadline. It’s 60 days from the date of the amended assessment. Put that date in your diary with a buffer. Don’t wait until day 58 to start preparing the objection.
Consider payment options. Can you pay under protest? If not, can you negotiate a payment plan? If the amount is large and enforcement action would be catastrophic, start thinking about whether you need to apply for a stay once you’ve lodged the objection.
Book a strategy meeting with your advisers within the first week. By the end of that meeting, you should have a clear plan: are we objecting? On what grounds? What evidence do we need to gather? Who’s drafting the objection? What’s the timeline?
Scenario 2: Data-matching amendment (income discrepancy)
You’re a director of a small business. The ATO has issued an amended assessment saying your company’s declared income is lower than the bank deposits they’ve identified through data-matching. They’ve assumed the difference is undeclared income.
What to do now:
Pull your bank statements for the relevant period. Go through every deposit. Can you identify what each deposit represents? Some might be loans, reimbursements, transfers between accounts, or non-assessable receipts. You need to reconcile the bank data with your accounting records and explain every discrepancy.
Prepare a spreadsheet showing the ATO’s assumed income, your declared income, and the difference, with an explanation for each item the ATO has picked up.
If the discrepancy is genuine (you did under-declare income), the smart move is usually to accept the amended assessment and negotiate on penalties. If the discrepancy is explained by non-assessable receipts or accounting differences, you have grounds to object.
Get advice on the strength of your explanation. If you can back it up with invoices, loan agreements, or other documents, lodge an objection. If your explanation is “I think those deposits were something else but I don’t have records”, your objection is unlikely to succeed.
Scenario 3: R&D tax incentive adjustment
You’re the CFO of a mid-size tech company. The ATO has reviewed your R&D claim and disallowed a significant portion of the expenditure, saying it doesn’t meet the R&D definitions. The amended assessment claws back the R&D offset you claimed, resulting in a large tax bill.
What to do now:
Get the ATO’s explanation of why the expenditure was disallowed. Was it because they think the activities weren’t R&D? Or because they think the expenditure wasn’t directly related to R&D?
Gather your R&D documentation: project plans, technical reports, timesheets, cost allocation records, and anything else that shows how the expenditure relates to eligible R&D activities.
If your R&D claim was prepared by an R&D consultant, brief them immediately and ask them to review the ATO’s reasons and assess whether the disallowance is justified.
R&D disputes often turn on technical and scientific questions, not just tax law. You might need technical experts as well as tax lawyers to mount an effective objection.
Consider the broader impact. If this year’s claim has been disallowed, are future years at risk? Is the ATO likely to review your R&D claims for other years? You need advice on how to manage the broader compliance risk.
Scenario 4: You’re close to the objection deadline
You received the amended assessment four weeks ago but didn’t focus on it immediately. Now you’re two weeks from the 60-day deadline.
What to do now:
Stop everything. This is urgent. If you miss the deadline, you lose your objection rights unless the ATO grants you an extension (which they might not).
Get advice today. Even if you’re not ready to prepare a full objection, get interim advice on whether objecting makes sense and what the key issues are.
If you decide to object, lodge the objection within the deadline. It doesn’t have to be perfect. You can provide additional evidence and submissions later if needed, but you must lodge something in the approved form within 60 days.
If you’re genuinely not ready and you’re going to miss the deadline, prepare an extension of time application immediately. You’ll need to explain why you couldn’t lodge on time and why it’s reasonable to allow a late objection. The sooner you apply, the better your chances.
Scenario 5: You can’t pay the amended assessment
You’ve decided to object, but the amended assessment is for an amount you can’t pay upfront. Your business doesn’t have the cashflow.
What to do now:
Contact the ATO within the first week. Explain that you’re objecting and that you want to negotiate a payment arrangement.
Prepare a cash flow forecast showing what you can realistically pay each month. Be honest. If you propose a payment plan you can’t meet, you’ll default and the ATO will move to enforcement.
At the same time, get advice on whether you should apply for a stay of recovery once the objection is lodged. If enforcement action would push your business into insolvency and you have a reasonable objection, a stay might be the right strategy.
Don’t ignore the payment issue and hope it goes away. It won’t. The ATO will escalate to enforcement if you don’t engage.
The first week after receiving an amended assessment is critical. That’s when you set the direction: are you accepting it, negotiating it, or fighting it? Once you’ve made that call, the rest follows. But you need to make the call quickly, with the right advice, and with your eyes open to the practical consequences.
Final Thoughts: Clarity in the Face of a Dispute
Amended assessments are disruptive. They change your numbers, your plans, and often your relationship with the ATO. But they’re not the end of the story. You have options.
The key is to approach the decision methodically. Understand what the ATO is saying, assess whether they’re right, weigh the commercial risks and costs, and choose the pathway that makes sense for your business.
If you decide to challenge the assessment, do it properly. A rushed, under-prepared objection is worse than no objection at all. Take the time to gather your evidence, build your argument, and present a case that the ATO (or the AAT, or the Federal Court) has to take seriously.
And if you’re not sure whether to challenge it, get advice early. The cost of advice in the first week is almost always lower than the cost of making the wrong call and living with the consequences for years.
Litigation is complex. But the pathway shouldn’t be.
At Aptum Legal, we partner with clients facing ATO disputes to identify what matters, make the right decisions, and execute with rigour. If you’ve received an amended assessment and you’re weighing your options, we can help you assess your position and map out the best path forward.
Disclaimer: This article provides general information only and does not constitute legal advice. Every tax dispute depends on its specific facts and circumstances. If you’ve received an amended assessment or are considering challenging an ATO decision, you should obtain advice tailored to your situation.
