It’s that time of year again. You’ve just survived the end of the financial year, and now tax season is staring you in the face. Whether you’re planning to do it yourself or hand it off to an accountant, there’s that quiet voice in the back of your mind asking, “Did I forget anything?”
If you’re like most Australians, you probably just want your tax return done and dusted, ideally with a decent refund and zero issues with the ATO. But rushing through it or relying on old advice could leave you open to mistakes. And when it comes to the ATO, even small slip-ups can have bigger consequences than you might expect.
The good news? You’re not alone. And a little awareness now can save you time, stress, and potentially a lot of money later. Let’s take a look at some of the most common tax return mistakes Aussies are making in 2025 and how you can make sure they don’t happen to you.
1. Rounding Figures or Guessing Amounts
It’s tempting to round figures when you’re filling out your return. After all, who remembers the exact amount they earned from a side job or the total spent on work-related expenses throughout the year?
But guessing or rounding could cost you.
The ATO has access to more third-party data than ever before. This includes income from employers, banks, government agencies, and even digital platforms. If your return does not match what they already know, you may be asked to explain.
Accuracy matters. Instead of estimating, refer to your payslips, invoices, or bank records. It may take a little longer, but it is worth the effort.
2. Claiming Deductions Without Proper Evidence
Many people still believe that they can claim up to $300 in work-related expenses without needing any proof. The truth is that while receipts are not required for amounts under $300, you must still have spent the money and be able to show how it relates to your job.
The ATO expects you to be able to explain every deduction you claim.
This includes what you bought, how much it cost, and how it was used for work. Simply saying “it was for work” is not enough. If you cannot provide that explanation, the deduction could be knocked back. That refund you were hoping for might turn into a debt instead.
3. Leaving Out Income from Side Jobs or Freelance Work
Have you earned a bit of extra cash this year from selling goods online, doing rideshare work, or freelancing in your spare time?
Many Australians earn extra income outside of their main job, but some assume that if they were paid in cash, or it was just a few hundred dollars, it does not need to be declared. Unfortunately, that assumption can lead to penalties.
All income must be declared. That includes one-off jobs, part-time work, and even occasional sales from platforms like Airbnb or Etsy. The ATO’s data-matching technology is improving every year. If you received income and did not report it, there is a strong chance they will find out.
4. Lodging Too Early
We get it. You’re hoping for a refund and just want to get your tax return sorted. And with the new financial year kicking off on 1 July, it’s tempting to get in early and lodge straight away. But if you filed before your income details were finalised, you might have jumped the gun.
By mid-July, a lot of people have already submitted their returns.
What many don’t realise is that some of the key information, like income from your employer, bank interest, private health cover, or government payments, might not have been fully reported to the ATO yet.
If you lodged early and left out something without knowing, it can trigger a review. Or worse, you might have to amend your return later, which slows everything down and can put your refund at risk.
If you haven’t lodged yet, this is a better time to do it. By now, most income and deduction details are starting to appear in the ATO’s systems, making it easier to cross-check and avoid errors. But don’t assume everything is perfect. It’s still worth reviewing every figure yourself before clicking submit.
Tax time doesn’t reward speed; it rewards accuracy. A little patience now can save you the hassle of fixing mistakes later.
5. Incorrect Home Office Claims
Working from home has become the new normal for many. But that does not mean you can automatically claim a portion of your rent, electricity, or internet.
The ATO updated its method for calculating home office expenses from 1 July 2022. The new fixed rate method requires a record of the actual hours you worked from home, not just a rough estimate.
If you are claiming using this method, you also need to keep evidence of the additional running costs, such as power bills and phone usage. Without records, your claim could be disallowed.
6. Failing to Keep Proper Records Throughout the Year
You cannot claim what you cannot prove. And trying to find receipts a week before the deadline often leads to frustration, missed deductions, or rushed decisions.
Keeping track of expenses throughout the year is one of the easiest ways to make tax time less stressful. Use a digital folder, an app, or even a simple spreadsheet to log purchases as you go. Take photos of receipts and keep a record of work-related travel and hours worked from home.
Good habits now will save you time, money, and stress later.
7. Relying on Unqualified Advice or Leaving It Too Late to Get Help
There’s always someone who claims to know a shortcut when it comes to taxes. Maybe it’s a friend who “knows a guy,” or a social media post promising quick wins. But unless the advice is coming from a registered tax professional, it could land you in trouble.
Only registered tax agents are legally allowed to prepare and lodge tax returns on your behalf. They’re also required to stay across changes to tax law, which means you’re less likely to miss out on deductions or make costly mistakes.
If you’re thinking of getting professional help, don’t wait until the deadline is breathing down your neck. The earlier you speak to a professional, the more support you’ll have in reviewing your paperwork, identifying claims, and making sure everything adds up.
At Clear Tax, we’re a team of qualified tax accountants who help individuals and businesses across Australia get their returns right the first time. We don’t just lodge your return — we look for every opportunity to help you stay compliant, avoid penalties, and make the most of your deductions.
Don’t leave it to chance or the last minute. Get in touch with Clear Tax today and let a professional take it from here.
In Summary: Don’t Let Simple Mistakes Cost You
Tax time is not just about ticking boxes. It is about making sure your information is complete, your claims are accurate, and your paperwork is ready if anyone asks.
Mistakes might not feel like a big deal when you are doing your return, but they can have serious consequences. Missed refunds, penalties, or audits are all possibilities if you do not get it right.
You do not need to be an expert, but you do need to be careful. Take your time, check your records, and if anything feels uncertain, speak to someone who understands the rules.
Because when it comes to your money, a little effort now can save a lot of trouble later.
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