How to Fix Mistakes After Lodging (2025 Guide)

You Lodged Your Tax Return and Found a Mistake – What Now? Mistakes on tax returns are more common than you think — and the good news is, they’re fixable.

At Tax NextGen, we regularly help Australian individuals, small business owners, freelancers, and students amend their tax returns quickly and correctly, reducing the risk of penalties or ATO audits.

In this guide, you’ll learn:

  • When to amend your tax return
  • How to lodge an amendment online or through a tax agent
  • How long it takes the ATO to process changes
  • Common pitfalls to avoid
  • Why professional help can save you time, money, and stress

When Should You Amend a Tax Return?

According to the Australian Taxation Office (ATO), you should lodge an amendment if you:

  • Forgot to include income
    Examples: casual or freelance work, bank interest, dividends, or investment earnings
  • Missed deductions
    Examples: work-from-home expenses, travel, professional memberships, or donations
  • Entered incorrect personal details
    Examples: wrong tax file number (TFN), name, address, or income amounts

Why it matters:

Even small errors can result in incorrect tax assessments, underpaid taxes, or overpaid refunds, potentially triggering ATO audits or penalties later.

How to Submit an Amended Tax Return in Australia

There are two main ways to amend a tax return

1. Online via myGov

  • Step 1: Log in to your myGov account linked to the ATO.
  • Step 2: Navigate to your lodged tax return.
  • Step 3: Select ‘Amend’ and update the necessary details.
  • Step 4: Submit changes directly online.

Cons of Amending/Filing Tax Returns via myGov:

  • Limited for Complex Tax Situations
    Not ideal if you have capital gains, foreign income, business income, or trust distributions.
  • Higher Risk of Errors
    Self-lodging increases the chance of mistakes, which could lead to ATO audits or penalties.
  • Delayed Processing of Amendments
    Amended returns can take up to 20 business days (or longer during peak periods) to be processed.
  • Lack of Personalised Guidance
    Only basic help is available; no tailored advice like you’d get from a tax agent.
  • Refund or Payable Not Instantly Updated
    Changes to refund amounts or debts aren’t shown immediately after submitting an amendment.
  • Not All Years Can Be Amended Online
    Only certain recent years are available for amendment through myGov — older returns may need paper forms or agent assistance.

2. Through a Registered Tax Agent (like Tax NextGen)

  • Provide your original tax return and details of the correction.
  • Your agent will prepare and submit the amendment on your behalf.
  • You get expert review, error checking, and peace of mind.

Good to know:
You can submit multiple amendments if you discover more errors later.

How Long Does It Take the ATO to Process an Amendment?

  • The ATO generally processes amended tax returns within 20 business days.
  • Any refund adjustments or extra tax owed will be automatically updated in your tax assessment.

Pro tip: You can track your amendment’s progress through your myGov account under the “Track my return” section.

Common Mistakes to Avoid When Amending Your Tax Return

  • Rushing the amendment → Double-check all figures before resubmitting.
  • Ignoring known mistakes → The ATO’s data-matching systems will likely detect them.
  • Failing to keep confirmation → Always save amendment reference numbers and receipts for your records.

Why Use Tax NextGen to Amend Your Tax Return?

At Tax NextGen, we bring:

  • Expertise: Registered tax agents with years of experience across industries and income types.
  • Accuracy: We cross-check your data to minimise risks and ensure the ATO receives complete, compliant amendments.
  • Speed: We submit amendments efficiently to help you avoid delays or penalties.
  • Support: We handle communication with the ATO, so you don’t have to.

Even if you lodged through another provider (or did it yourself), we can help fix it.

Need Help Amending Your Tax Return? You don’t have to do it alone.

Book a free consultation with a Tax NextGen expert today

Lodge securely online via www.taxnextgen.com.au

We’re here to make tax stress-free for individuals, families, gig workers, international students, and small business owners across Australia.