Written by
Ilyas Omari
Reviewed by
To reactivate a cancelled ABN in Australia, you need to re-apply through the Australian Business Register (ABR). In most cases, the ABR will reissue your original ABN number. The process takes around 24 hours and you can do it yourself through the ABR website or let Lawpath handle it for you.
- You re-apply, you don’t “reinstate” your ABN. There is no separate reinstatement button. A cancelled ABN requires a fresh application through the ABR, which typically reissues your original number if it’s the same business entity.
- It takes around 24 hours once submitted online. Complex cases (where details have changed significantly or the ABN has been cancelled for many years) can take longer.
- Your GST registration does not come back automatically. If you were registered for GST before the cancellation, you’ll need to re-register separately. Trading above $75,000 without active GST registration creates a backdated liability.
- Quoting a cancelled ABN is an offence. The ATO can impose penalties for using an inactive ABN on invoices. If clients pay you without a valid ABN on the invoice, they’re legally required to withhold 47% of the payment.
- If your business structure has changed, you may need a new ABN entirely. Changing from a sole trader to a company, or starting a completely different type of business, means a fresh application. Not a reactivation.
If you’ve just discovered your ABN is cancelled, you’re probably in one of two situations: you cancelled it yourself when you stopped trading, or the ATO cancelled it for you without you realising. Either way, the fix is the same. But before you apply, it’s worth spending two minutes understanding why this happened. If your structure or business type has changed, you might be applying for the wrong thing.
Why was my ABN cancelled?
The ABR can cancel an ABN for a few reasons. The most common is inactivity. If the ATO sees no lodgements, no GST reporting, and no business income across multiple tax periods, they’ll conclude you’re no longer carrying on an enterprise and cancel your ABN. This can happen without any notice, which is why many business owners discover the cancellation only when a supplier or client flags it.
The other common causes are a direct cancellation request (you or your accountant told the ABR you were done trading), a business structure change (say, from sole trader to company), or incorrect information being updated on the register. In all of these cases, you’ll need to re-apply.
The pattern seen across businesses who contact Lawpath about ABN issues is that many didn’t realise the ABN had been cancelled. They’ve been invoicing clients for months, sometimes longer, with a number that shows as cancelled on the public register. Those clients were technically required to withhold 47% of payments made without a valid ABN. That’s a problem that can unwind very quickly if the ATO picks it up.
Check your current ABN status now at ABN Lookup before going further. If it shows “Cancelled”, proceed below. If it shows “Active” but your details are wrong, you don’t need to reactivate. You need to update your details within 28 days of the change.
Can I get my old ABN back, or do I need a new one?
This is the question most people get wrong. The honest answer depends on whether the underlying business entity is the same.
Use this table as a quick guide:
| Your situation | What you need |
|---|---|
| Same sole trader business, just paused trading | Re-apply through ABR. You’ll likely get your original ABN back |
| Same company (same ACN), ABN was cancelled | Re-apply through ABR. You should get the same ABN back |
| Sole trader who now wants to operate as a company | Register a new company (new ACN + new ABN) |
| Starting a completely different type of business | Apply for a new ABN. It’s a different enterprise |
| ABN cancelled due to incorrect details on the register | Contact the ABR directly to request a correction or re-apply |
The ABR decides whether to reissue your original ABN number or issue a new one. For sole traders re-registering the same business, the original number is almost always reissued. For companies, the ABN ties to the ACN. So as long as the company still exists (hasn’t been deregistered with ASIC), the ABN should be recoverable.
If you’re moving from sole trader to company, don’t try to reactivate your existing ABN. That number belongs to you as an individual. Your new company needs its own ACN and ABN. You can register a new company through Lawpath if you’re going down that path.
How to reactivate a cancelled ABN: step by step
Once you’ve confirmed your ABN is cancelled and you’re re-registering the same business entity, the process is straightforward. You can do it yourself through the ABR, or Lawpath can handle the whole thing and typically have your ABN active again within 24 hours.
Step 1: Check your ABN status and gather your details
Go to the ABN Lookup tool and search your ABN. Confirm it shows as “Cancelled” and note your cancellation date. You’ll also want to have the following ready before you apply:
- Your Tax File Number (TFN)
- Your contact details: email, phone, and a physical address (not a PO box)
- The date you want the ABN to be effective from
- The states and territories your business operates in
- Your previous ABN number (shown on the ABR lookup result)
- If you want to nominate an authorised contact (like an accountant), their details
Step 2: Complete the application
You can re-apply through Lawpath’s ABN registration service or directly through the ABR website. On the Lawpath form, when the application asks if you’ve previously had an ABN, select “Yes” and enter your existing ABN number. This flags to the ABR that this is a reactivation, not a new application.
Answer the business activity questions accurately. The ABR uses this information to assess whether you’re still carrying on an enterprise which is the eligibility requirement for having an ABN. If you’ve been inactive for an extended period, be ready to explain what you’re doing now and when you plan to resume trading. Overstating activity creates problems later, so be accurate.
Step 3: Handle your GST and business name registration
This step trips up a lot of people. If your business earns $75,000 or more per year (or $150,000 for non-profits), you must be registered for GST. Your ABN reactivation does not automatically re-register you for GST. That’s a separate step.
On the Lawpath ABN form, you can request GST registration at the same time as reactivating your ABN. Do this if you’re over the threshold, or if you want to claim input tax credits on business purchases. If you’ve been trading above the threshold without active GST registration, you may have a backdated GST liability to address. Your accountant can help you work out what’s owed.
Similarly, if you had a registered business name, check whether it’s still active via Lawpath’s business name service. Business name registrations don’t cancel automatically when an ABN is cancelled, but they expire every one or three years. A lapsed business name needs to be renewed separately.
Step 4: Submit and confirm
Once you’ve submitted, your ABN status will update to “Active” on the public register usually within 24 hours for straightforward applications. If additional information is required, the ABR will contact you. Once active, download or screenshot the confirmation for your records.
What to update after your ABN is reactivated
Getting the ABN back is step one. The part most guides skip is what happens next. Here’s a short checklist of things to update once your ABN is active again:
- Accounting software: Update your ABN in Xero, MYOB, or QuickBooks so it appears correctly on future invoices
- Invoice templates: Check that your ABN is displaying correctly on all invoice templates especially if you send invoices through a third-party platform
- Supplier and client records: Let regular clients know your ABN is active again, particularly any who were withholding payments
- Bank accounts and payment platforms: Some payment platforms link to ABN details verify these are still correct
- MyGovID and RAM: If you access the ATO’s online services on behalf of your business, make sure your Relationship Authorisation Manager (RAM) access is still linked to your reactivated ABN
- GST re-registration: If you didn’t handle this during the application, do it now through your ATO Business Portal if you’re above the $75,000 threshold
What we see in Lawpath consultations
A few patterns come up repeatedly when businesses deal with ABN cancellation issues.
The most common one: a business owner reactivates their ABN but doesn’t re-register for GST, then continues invoicing at the same rates they used before the cancellation. Six months later, the ATO flags that they’ve been collecting what looks like GST (prices inclusive of 10%) without a GST registration. The resulting backdated liability can be significant. The fix is simple: re-register for GST at the same time as reactivating your ABN. It’s an easy step to miss when you’re focused on just getting the ABN back.
The second pattern: businesses that have been trading with a cancelled ABN for a while assume they can just backdate the reactivation to cover the gap. The ABR will allow you to nominate a start date for your ABN reactivation, but this doesn’t erase the period where you were technically operating without one. If you’ve issued invoices during the gap, those invoices were technically non-compliant. For most small businesses this doesn’t result in penalties, but if a client withheld payment because of the missing ABN, you may need to sort that out directly.
The third: owners who closed a business and then want to start something new assume they can reactivate the old ABN. If it’s a genuinely different enterprise (different activity, different business structure), the ABR may issue a new ABN rather than reactivate the old one. This is the right outcome. A new business should start clean.
What happens if you trade with a cancelled ABN?
Quoting a cancelled or inactive ABN on an invoice is an offence under the A New Tax System (Australian Business Number) Act 1999 (Cth). The practical consequences are worth understanding:
- Withholding: If you don’t quote a valid ABN, businesses that pay you are required to withhold 47% of the payment (the top marginal tax rate) and send it to the ATO. This is called no-ABN withholding.
- GST liability: If you were collecting GST-inclusive prices but not registered for GST, the ATO may treat the GST component as income you owe, not GST you collected on their behalf.
- Penalties: The ATO has discretion to apply administrative penalties for incorrect ABN use, though in practice, first-time breaches where the business corrects quickly often result in warnings rather than fines.
The risk is real but manageable. Get the ABN reactivated, get GST sorted, and contact the ATO proactively if you’ve been trading during the gap. Proactive disclosure is treated much better than being caught.
How to stop your ABN being cancelled again
Once you’re back up and running, a few simple habits will keep the ABR from cancelling your ABN a second time.
Keep your ABR details current. You’re legally required to update your ABN details within 28 days of any change: address, contact details, business structure, the states you operate in. The ABR cancels ABNs partly because details go stale and the register can’t verify the business is still operating. Log into the ABR portal and run through your details once a year.
Lodge your tax returns and BAS on time, even if they’re nil. The ATO’s cancellation trigger is activity signals, or rather the absence of them. No lodgements for several years is a signal that the business has stopped. Lodging a nil BAS tells the ATO the business is still registered and active, even if it’s been a quiet period.
Don’t cancel your ABN when you take a break. If you’re going on leave, pausing a side business, or just having a slow period, don’t cancel your ABN. The reactivation process is quick and easy, but the gap period creates compliance risk. Keeping it active costs you nothing.
Frequently asked questions
Can I reactivate my old ABN and keep the same number?
In most cases, yes. If you’re re-registering the same business entity (for example, the same sole trader activity or the same company), the ABR will typically reissue your original ABN number. You’ll need to include your previous ABN on the application so the ABR can match it.
Do I reactivate my ABN or just update it?
Check your ABN status first at ABN Lookup. If the status shows ‘Cancelled’, you need to re-apply. If it shows ‘Active’ but with outdated information, you need to update your details. You don’t need to re-apply. Active ABN details must be updated within 28 days of any change.
How long does it take to reactivate an ABN?
An ABN typically reactivates within 24 hours of the online application being submitted. Applications that require additional review (such as significant changes in business activity or long cancellation gaps) can take longer. There is no way to pay to expedite the process.
How much does it cost to reactivate an ABN?
Reactivating an ABN directly through the ABR website is free. If you use Lawpath’s ABN registration service, visit the ABN registration page for current pricing. Lawpath’s service handles the application on your behalf and includes same-day turnaround.
What happens if your ABN is inactive?
A cancelled ABN means your business has no valid identification for tax purposes. Clients and suppliers can withhold 47% of payments made without a valid ABN on invoices. If your business earns over ,000 per year, you also can’t legally trade without an active ABN and GST registration.
Does my GST registration come back when my ABN is reactivated?
No. GST registration is separate from your ABN. If you were registered for GST before the cancellation, you’ll need to re-register through the ABR or ATO Business Portal. If your business earns over $75,000 per year, re-registering for GST is mandatory.
How long does an inactive ABN last before it gets cancelled?
There is no fixed automatic cancellation period. The ABR cancels ABNs when it forms the view that the holder is no longer carrying on an enterprise typically based on missed lodgements, no reported business activity, or significantly outdated register details. This can happen in as little as one to two years of inactivity.
What is the new ABN process for a company?
If you previously had a company ABN and the company has since been deregistered with ASIC, you cannot reactivate that ABN. You’ll need to register a new company (which gets a new ACN) and apply for a new ABN. If the company still exists on the ASIC register, the ABN can typically be reactivated by re-applying through the ABR.
Getting your ABN back is one of those tasks that sounds harder than it is. Most sole traders are done in under 20 minutes. The part that catches people out is what comes after: GST, invoicing touchpoints, supplier notifications. Run through the checklist above and you’ll avoid the issues that turn a simple reactivation into a messy tax problem.
If your ABN is cancelled and you’d rather not deal with the paperwork, Lawpath can reactivate your ABN on your behalf, typically within 24 hours. Get it sorted today and get back to business.
