Making a mistake on your tax return can be stressful, especially if you are unsure whether the error could lead to penalties or an unexpected tax bill. The good news is that not every tax return mistake is treated as tax fraud, and many errors can be corrected.

A mistake could be as simple as entering the wrong amount, forgetting to include income, incorrectly calculating a deduction or misunderstanding whether an expense is tax-deductible.

As John Saade and the team at Latitude Accountants emphasise, good tax management is not about being perfect every time. It is about keeping accurate records, understanding your obligations and taking the appropriate action when something goes wrong.

If you discover an error in your tax return, the most important thing is not to ignore it.

What Counts as a Mistake on a Tax Return?

A tax return mistake can occur when information is accidentally reported incorrectly or something that should have been included is left out.

Common examples include:

• Entering the wrong income amount
• Forgetting to report some income
• Claiming an incorrect tax deduction
• Claiming too much of a work-related expense
• Using the wrong business-use percentage
• Entering information in the wrong section
• Forgetting certain investment income
• Providing incorrect personal or business information
• Making a calculation error
• Failing to include relevant foreign income
• Accidentally claiming an expense that is not deductible

Some mistakes may have little or no effect on your final tax liability, while others could result in a tax shortfall.

What Should You Do If You Make a Mistake on Your Tax Return?

If you discover an error, the first step is to identify what went wrong and determine whether your tax return needs to be corrected.

Do not simply assume that because your tax return has already been lodged, nothing can be done.

A sensible process is:

1. Identify the error.
2. Gather the relevant records.
3. Determine whether the mistake changed your tax position.
4. Speak with your accountant or tax adviser if necessary.
5. Correct or amend the return where appropriate.
6. Keep documentation showing how the error was addressed.

Taking action early can help prevent a relatively simple mistake from becoming a bigger problem.

Can You Amend a Tax Return After Lodging It?

In many circumstances, yes.

If you discover that information in your lodged tax return is incorrect, you may be able to request an amendment to correct the information.

For example, you might discover that you:

• Forgot to include investment income
• Claimed an expense incorrectly
• Entered the wrong income figure
• Missed an eligible deduction
• Used an incorrect amount for a business expense

The appropriate amendment process depends on your circumstances and the nature of the error.

Why Amending Your Return Matters

Leaving an incorrect tax return unaddressed can create unnecessary problems.

If the mistake resulted in too little tax being paid, correcting the return can help bring your tax affairs back into order.

If you discover that you actually overpaid tax, correcting the information may potentially result in an additional refund, subject to the applicable rules.

What Happens If You Underpaid Tax Because of a Mistake?

If an error caused you to pay less tax than you should have, correcting the return may result in additional tax becoming payable.

Depending on the circumstances, interest may also apply.

For example, imagine you accidentally claimed a $10,000 deduction that you were not entitled to. That deduction reduced your taxable income, which in turn reduced the amount of tax you paid.

If the deduction is later corrected, your taxable income may increase and you may need to pay the resulting tax difference.

This can be frustrating, but correcting the error is generally better than knowingly leaving inaccurate information on your tax return.

Will You Be Fined for Making a Tax Return Mistake?

Not necessarily.

There is an important distinction between an honest mistake and deliberately providing false or misleading information.

The consequences of an error can depend on factors such as:

• The nature of the mistake
• The size of the tax shortfall
• Whether reasonable care was taken
• Whether the mistake was accidental
• Whether the taxpayer acted recklessly or deliberately
• Whether the error was voluntarily corrected
• The taxpayer’s circumstances

An honest mistake does not automatically mean you will receive a penalty.

However, taxpayers should not assume that every error will be penalty-free. The circumstances need to be considered carefully.

What If You Made an Honest Mistake?

Honest mistakes can happen to anyone.

You might misunderstand a deduction, enter an incorrect figure, or forget about a small amount of income.

The important thing is what you do once you discover the error.

For example, if you realise after lodging your return that you accidentally claimed 100% of an expense when only 60% was work-related, you should review the situation and consider whether an amendment is required.

Don’t Try to Hide the Mistake

One of the worst approaches is to discover an error and deliberately do nothing because you hope it will never be noticed.

If you know that your tax return contains incorrect information, professional advice can help you understand how to address it properly.

Correcting a mistake demonstrates a very different approach from deliberately maintaining an inaccurate tax position.

What If You Forgot to Declare Income?

Forgetting to declare income is another common tax return mistake.

Depending on your circumstances, income that may need to be reported can include:

• Salary and wages
• Business income
• Investment income
• Interest
• Dividends
• Rental income
• Capital gains
• Certain foreign income
• Other assessable income

If you realise that you omitted income from a previous return, gather the relevant documentation and discuss the issue with your accountant.

The sooner you identify and address the problem, the easier it may be to resolve.

What If You Claimed a Deduction You Were Not Entitled To?

Incorrect deductions are another common source of tax return errors.

Examples include:

• Claiming private expenses as work expenses
• Claiming 100% of a mixed-use expense
• Claiming ordinary clothing as workwear
• Claiming private travel
• Claiming personal expenses through a business
• Claiming expenses without appropriate records

A deduction should generally have the required connection to earning assessable income and satisfy the relevant tax requirements.

If you are unsure whether an expense qualifies, it is better to ask before claiming it.

What If Your Accountant Made the Mistake?

If a tax return was prepared by an accountant or tax agent and you later discover an error, you should raise it with them promptly.

Your accountant can review:

• What information was originally provided
• How the error occurred
• Whether the return needs to be amended
• Whether additional tax is payable
• Whether interest or penalties may apply
• What steps should be taken to prevent the problem happening again

It is important to remember that taxpayers still have responsibilities regarding the information included in their tax returns.

Providing your accountant with complete and accurate records is therefore essential.

How Can You Avoid Tax Return Mistakes?

Prevention is generally easier than correction.

Before lodging your tax return, consider the following checklist:

• Review all income sources.
• Check your bank and investment records.
• Keep receipts for deductible expenses.
• Separate business and personal expenses.
• Check work-related expense calculations.
• Make sure mixed-use expenses are apportioned correctly.
• Review rental property records where applicable.
• Check capital gains information where relevant.
• Keep supporting documentation.
• Ask questions about unusual or significant transactions.

Business owners should also maintain proper accounting records throughout the year rather than trying to reconstruct everything at tax time.

Why Professional Tax Advice Can Help

Australian tax rules can become complicated, particularly when you have multiple income sources, investments, a business or expenses that have both private and business components.

An accountant can help you:

• Identify potentially deductible expenses
• Review your tax records
• Check calculations
• Identify potential errors
• Determine whether an amendment may be required
• Develop better record-keeping processes
• Plan your tax affairs more effectively

Professional advice is particularly valuable when an error could materially affect your tax position.

What If You Discover an Old Tax Return Error?

Discovering an error from a previous financial year can be concerning, but you should not automatically assume that the situation is beyond correction.

Start by gathering the relevant tax return, notices of assessment and supporting records.

Then discuss the matter with your accountant or tax adviser.

They can help determine:

• What the error was
• Which tax year it relates to
• Whether an amendment is available
• Whether additional tax may be payable
• Whether interest or penalties could apply
• What action should be taken

The appropriate response will depend on the specific circumstances.

Frequently Asked Questions About Making a Mistake on Your Tax Return

What happens if I make a small mistake on my tax return?

A small error may have little practical impact, but you should still consider whether it needs to be corrected. The appropriate response depends on the nature of the mistake and whether it affected your tax liability.

Can I correct a tax return after it has been lodged?

In many circumstances, yes. If incorrect information was included in your lodged return, you may be able to amend it.

Will the ATO automatically penalise me for making a mistake?

Not necessarily. Penalties depend on the circumstances, including the nature of the error and whether reasonable care was taken.

What happens if I accidentally claim the wrong deduction?

You should review the deduction and determine whether your tax return needs to be amended. If the incorrect deduction reduced your tax liability, additional tax and potentially interest may become payable.

What if I forgot to declare income?

Gather the relevant records and speak with your accountant or tax adviser. You may need to amend the relevant tax return.

Is an honest tax mistake considered tax fraud?

An honest mistake is not automatically tax fraud. Deliberately providing false or misleading information is a much more serious matter.

Should I contact my accountant if I discover an error?

Yes. If you are unsure about the significance of an error or how to correct it, professional advice can help you determine the appropriate next step.

Need Help Correcting a Tax Return Mistake?

Discovering an error does not mean you should panic or ignore it. The important thing is to understand what went wrong and take the appropriate steps to correct your tax affairs.

Latitude Accountants can help individuals and business owners review their tax position, understand their obligations and address tax return issues.

Latitude Accountants

📍 Sydney Olympic Park | Marrickville | Melbourne | Loxton
📞 1300 706 597
📧 info@latitudeaccountants.com.au

Speak with the Latitude Accountants team if you have questions about your tax return, deductions, amendments or tax planning.

Disclaimer

This article provides general information only and does not constitute financial, tax, accounting or legal advice. Australian tax laws and ATO requirements can change, and the appropriate treatment depends on individual circumstances. You should obtain professional advice from a qualified accountant or tax adviser before making decisions about your tax affairs.