Published: 29 March 2026

How to Cancel an ABN in Australia: A Complete Guide for 2025-26

Whether you're closing your business, returning to full-time employment, or simply winding down your side hustle, there comes a time when you may need to cancel your Australian Business Number (ABN). While registering an ABN is often the exciting first step of a new venture, cancelling it is an equally important administrative task that shouldn't be overlooked. Failing to cancel an ABN you no longer need can lead to unnecessary compliance obligations, unwanted tax correspondence, and even penalties if you don't lodge required returns.

In this comprehensive guide, we'll walk you through everything you need to know about cancelling your ABN in Australia. We'll cover when you should cancel it, how to do it step-by-step, what tax implications you need to consider, and how it affects your GST registration, superannuation, and other financial obligations. Whether you're a sole trader, contractor, or small business owner, this guide will help you close out your ABN properly and avoid headaches down the track.

When Should You Cancel Your ABN?

The Australian Taxation Office (ATO) expects you to cancel your ABN as soon as you stop carrying on an enterprise. This isn't something you should put off indefinitely. Common situations where cancelling your ABN is the right move include closing your business permanently, ceasing to trade as a sole trader, returning to full-time employment and no longer contracting, selling or transferring your business to another entity, retiring from business activities, or winding up a company or trust structure.

It's important to understand that simply earning less income or taking a break from your business isn't always a reason to cancel your ABN immediately. If you intend to resume trading in the future, you may choose to keep your ABN active. However, if you've definitively stopped operating, holding onto an active ABN means you'll continue to receive reminders about tax lodgements, BAS deadlines, and other compliance obligations. The ATO may also view an inactive ABN as a red flag, potentially leading to reviews or audits if returns aren't lodged.

Before you cancel, make sure you've tied up all loose ends. This includes lodging any outstanding tax returns or BAS statements, paying any outstanding tax debts, and notifying your clients, suppliers, and bank that you're ceasing operations. Taking care of these matters first will make the cancellation process smoother and help you avoid disputes or penalties after your ABN is closed.

How to Cancel Your ABN: Step-by-Step Process

Cancelling your ABN is a straightforward process that can be done online, by phone, or through a registered tax agent. The fastest and most convenient method is through the Australian Business Register (ABR) website or the ATO's online services. If you have a myGov account linked to the ATO, you can cancel your ABN directly through the Business Portal. Most cancellations are processed immediately, though in some cases it may take a few days.

To cancel online, log in to your myGov account and access the ATO's online services. Navigate to the "Business" section, select "ABN details," and choose the option to cancel your ABN. You'll need to provide the date you ceased business activities, which should be the actual date you stopped trading. Once submitted, you'll receive a confirmation that your ABN has been cancelled. You can also cancel by calling the ATO on 13 28 66, though you may experience longer wait times during peak periods.

If you prefer, you can ask your registered tax agent or accountant to cancel your ABN on your behalf. This is often the best option if you have complex tax affairs, outstanding lodgements, or questions about the implications of cancellation. Your tax agent can also ensure that all your final returns are lodged correctly and that you claim any remaining deductions you're entitled to before the ABN is closed.

Tax Obligations After Cancelling Your ABN

Cancelling your ABN doesn't eliminate your tax obligations for the period you were in business. You'll still need to lodge a final tax return covering all income earned up to the date you ceased trading. This return should include all business income, deductible expenses, and any other assessable income you received during the financial year. If you operated across two financial years, you may need to lodge returns for both years.

For the 2025-26 financial year, individual income tax rates apply to your business income just as they do to salary and wages. As a former sole trader or contractor, your total taxable income will be assessed at the following marginal rates. You can use our income tax calculator to estimate your final liability.

In addition to income tax, you'll need to account for the Medicare levy of 2% if your income is above the relevant threshold. Our Medicare levy calculator can help you work out exactly how much you'll owe. If you had private health insurance during the year, you may be eligible for the private health insurance rebate. Conversely, if you didn't have insurance and your income exceeded the surcharge thresholds, you may need to pay the Medicare Levy Surcharge.

If you've been making quarterly Pay As You Go (PAYG) instalments, cancelling your ABN may affect your final instalment. The ATO will usually issue a notice of assessment once your final tax return is processed, which will reconcile the instalments you've already paid against your actual tax liability. If you've overpaid, you'll receive a refund. If you've underpaid, you'll need to pay the difference by the due date to avoid interest charges.

GST Registration and Business Activity Statements

If your ABN was registered for GST, cancelling your ABN will generally also cancel your GST registration. However, you should confirm this separately to ensure there are no ongoing obligations. You'll need to lodge a final Business Activity Statement (BAS) covering the period up to the date you ceased trading. This final BAS should report all GST collected on sales and claim any GST credits you're entitled to on business purchases made before cancellation.

One important consideration when cancelling GST registration is the adjustment for business assets you retain. If you keep business assets such as vehicles, equipment, or inventory after cancelling your GST registration, you may need to make an increasing adjustment. This means you'll need to pay back some of the GST credits you previously claimed on those assets. The ATO has specific rules about how to calculate these adjustments, and getting them wrong can lead to penalties.

Make sure you keep all your BAS records, tax invoices, and receipts for at least five years after cancellation. The ATO can review your affairs long after your ABN is closed, and having proper documentation is your best defence if questions arise. If you're unsure about your final BAS obligations, consulting a registered tax agent is highly recommended.

Superannuation, HECS-HELP, and Salary Sacrifice Considerations

When you cancel your ABN and return to employment, your superannuation arrangements will change significantly. As a business owner or contractor, you were responsible for making your own super contributions. Once you're an employee again, your employer must make compulsory superannuation guarantee contributions on your behalf. For FY 2025-26, the super guarantee rate is 11.5% of your ordinary time earnings, increasing to 12% from 1 July 2025. You can explore how these contributions add up using our superannuation calculator.

If you made personal deductible super contributions while operating under your ABN, make sure you claim them in your final tax return. You'll need to submit a Notice of Intent to Claim a Tax Deduction to your super fund and receive an acknowledgment before you lodge your return. For FY 2025-26, the concessional contributions cap is $30,000, so ensure your total employer and personal contributions don't exceed this limit.

If you have a HECS-HELP debt, your repayment obligations will continue regardless of whether you have an ABN or are employed. For the 2025-26 financial year, the repayment threshold is $67,000, with rates ranging from 1% to 10% depending on your total repayment income. When you become an employee, your employer will withhold HECS-HELP repayments from your salary. However, if your ABN income for the year pushes you into a higher repayment bracket, you may owe additional amounts at tax time. Use our HECS-HELP calculator to estimate your repayment obligations.

Returning to employment also opens up salary sacrifice opportunities that may not have been available or practical when you were self-employed. Salary sacrificing into superannuation, a car lease, or other fringe benefits can reduce your taxable income and improve your overall financial position. It's worth discussing these options with your new employer or a financial adviser once your ABN is cancelled.

What If You Change Your Mind?

Sometimes circumstances change, and you may decide to go back into business after cancelling your ABN. The good news is that you can reapply for the same ABN if it hasn't been allocated to someone else. However, there's no guarantee you'll get the exact same number back, so it's worth thinking carefully before cancelling if you believe you might resume trading within the next 12 months.

If you do reapply, you'll go through the same eligibility assessment as a first-time applicant. The ATO will want to see that you're genuinely carrying on an enterprise and that your business activities are legitimate. Having a history of cancelled and reinstated ABNs isn't necessarily a problem, but frequent cancellations could raise questions about the genuineness of your business.

Summary: Closing Your ABN the Right Way

Cancelling your ABN is a simple but important step when you stop operating a business or working as a contractor in Australia. The process can be completed online through myGov, by phone, or through a tax agent, and most cancellations are processed quickly. However, the administrative work doesn't end there. You'll still need to lodge final tax returns and BAS statements, settle any outstanding tax debts, and consider the implications for your superannuation, GST, and other financial arrangements.

For the 2025-26 financial year, make sure you understand how your final business income will be taxed, whether you need to make GST adjustments, and how your transition back to employment affects your super and HECS-HELP obligations. Taking the time to close out your ABN properly will save you stress, money, and potential penalties in the long run.

Whether you're wrapping up a side hustle, closing a long-running business, or moving back into the workforce, MyPayAU is here to help. Use our calculators to estimate your take-home pay, income tax, superannuation, Medicare levy, HECS-HELP repayments, and salary sacrifice options so you can move forward with confidence in FY 2025-26.