Disagreeing with a decision from the Australian Taxation Office (ATO) or another government agency can be frustrating. Fortunately, Australians have the right to request an independent review through the Administrative Appeals Tribunal (AAT appeal) process. However, many applicants make simple yet costly mistakes that can delay or even damage their chances of success.
If you’re preparing to lodge an AAT appeal in 2025, it’s essential to understand what not to do. In this guide, we’ll highlight the most common mistakes people make—and how to avoid them—to ensure a smoother and more effective appeal experience.
Understanding the Administrative Appeals Tribunal (AAT Appeal)
The Administrative Appeals Tribunal (AAT appeal) is an independent body that reviews decisions made by Australian government agencies, including the ATO, Centrelink, and others. Its role is to ensure decisions are fair and legally correct.
Unlike court proceedings, the AAT appeal process is designed to be more accessible, allowing individuals and businesses to present their case without needing to go through a full court trial. Still, success depends heavily on preparation, accuracy, and timely action.
Mistake #1: Missing the Lodgment Deadline
One of the most common and serious mistakes is failing to lodge the appeal on time. In most tax-related matters, you have 60 days from the date of the ATO’s objection decision to file your AAT application.
If you miss this deadline, the AAT might not accept your appeal unless you can show valid reasons for the delay. While extensions can be requested, approval is not guaranteed. Therefore, it’s crucial to act quickly once you receive the ATO’s decision letter.
Tip: Mark your calendar as soon as you receive the decision and begin gathering necessary documents right away.
Mistake #2: Submitting Incomplete or Incorrect Information
Accuracy matters. Submitting incomplete forms, missing documents, or incorrect details can cause unnecessary delays or even lead to dismissal.
When lodging your Administrative Appeals Tribunal (AAT appeal), ensure you provide:
A copy of the ATO objection decision
All relevant supporting documents
A clear explanation of why you disagree with the ATO’s decision
Incomplete submissions often force the AAT to request additional information, slowing the process.
Tip: Double-check your application before submitting it and, if possible, ask a professional to review it for accuracy.
Mistake #3: Not Providing Enough Evidence
The AAT bases its decisions on facts, not opinions. Many applicants fail to support their claims with proper evidence, which weakens their case.
For example, if you’re disputing a tax deduction or GST claim, you’ll need records such as invoices, bank statements, or contracts to prove your position. Without evidence, the Tribunal is unlikely to overturn the ATO’s decision.
Tip: Gather and organise all documentation that supports your case before the hearing. Label files clearly to make them easy to reference during discussions.
Mistake #4: Ignoring Communication from the AAT or ATO
Once your AAT appeal is lodged, both the AAT and the ATO may send requests for information, scheduling updates, or invitations to conferences. Ignoring these messages can harm your appeal.
Failure to respond might signal to the Tribunal that you’re not taking the process seriously, which can delay proceedings or lead to dismissal.
Tip: Check your email and postal mail regularly, and respond to all AAT or ATO correspondence promptly. Keep copies of everything you send or receive.
Mistake #5: Failing to Prepare for the Case Conference or Hearing
Many applicants underestimate how important preparation is for case conferences and hearings. The AAT uses these meetings to clarify issues, explore settlement options, and identify the evidence each side will rely on.
Walking in unprepared can make your arguments appear weak or inconsistent. This is one of the biggest reasons small businesses and individuals lose their appeals.
Tip: Review your documents thoroughly, practice explaining your position clearly, and anticipate the questions that may arise during the hearing.
Mistake #6: Not Seeking Professional Advice
While you’re allowed to represent yourself in an AAT appeal, doing so without expert guidance can be risky—especially if your case involves complex tax or legal issues.
Tax agents, accountants, or lawyers familiar with AAT processes can help you present a stronger case. They know what the Tribunal expects and can identify errors or weaknesses in your documentation before submission.
Tip: Even if you plan to represent yourself, consider getting a professional consultation early to ensure you’re on the right track.
Mistake #7: Overlooking Settlement Opportunities
Not every Administrative Appeals Tribunal (AAT appeal) needs to go all the way to a hearing. In fact, many cases are resolved during early discussions or case conferences.
Some applicants refuse to consider settlement options, believing it means admitting fault. However, settlements can save time, money, and stress while still achieving a fair outcome.
Tip: Stay open-minded during negotiations. If the ATO offers a reasonable resolution, it may be in your best interest to accept it.
Mistake #8: Using Emotional Arguments Instead of Facts
It’s understandable to feel frustrated, especially if you believe the ATO made an unfair decision. However, emotional appeals rarely influence the Tribunal.
The AAT focuses on evidence, documentation, and the law. Complaining about the ATO’s behaviour or using emotional language can distract from your main arguments.
Tip: Keep your statements factual and concise. Focus on evidence that supports your position and aligns with the law.
Mistake #9: Poor Organisation of Documents
Disorganised records can make your case harder to follow. If you hand over a pile of unsorted paperwork, it’s difficult for the AAT to identify key evidence.
A well-structured document set, with labelled folders or digital files, shows professionalism and helps the Tribunal understand your case more efficiently.
Tip: Create a checklist and organise documents by category—such as correspondence, financial records, and statements.
Mistake #10: Expecting Instant Results
An Administrative Appeals Tribunal (AAT appeal) can take several months—or even over a year—to complete, depending on case complexity and workload. Many applicants become impatient or frustrated when decisions take longer than expected.
It’s important to understand that each case undergoes detailed review to ensure fairness. Staying patient and responsive throughout the process helps maintain momentum.
Tip: Track your case status online and stay in contact with your AAT case officer for updates.
Final Thoughts
Lodging an Administrative Appeals Tribunal (AAT appeal) gives you the chance to challenge decisions and seek a fair outcome. However, success depends on preparation, accuracy, and awareness of the process.
By avoiding the mistakes outlined above—such as missing deadlines, submitting incomplete documents, or failing to provide evidence—you’ll improve your chances of a positive result.
In 2025, with online applications and digital hearings becoming more efficient, staying organised and proactive is easier than ever. Whether you handle your appeal independently or with professional support, taking the right steps can make all the difference in achieving a fair resolution.
