If you have forgotten your ABN, search your own name or business name free on ABN Lookup — it is a public register, so no login is needed. If the ABN is not in your own name, sign in to ATO online services through myGov, where your ABN appears under Business. Both are free, and neither needs an agent.
Three places your ABN is sitting right now
- ABN Lookup — abr.business.gov.au. Search your name or trading name. Sole trader ABNs are registered against your legal name, so search that, not the name you trade under. Free, no login.
- myGov, then ATO online services — sign in, link the ATO service, and your ABN shows under the business section. This is the one to use if the public search returns several people with your name.
- Your own paperwork — any tax invoice you have issued, your last income tax return, your BAS, or the original confirmation email from the ABR. An ABN has to appear on every invoice you issue, so an old invoice is the fastest place to look.
Check whether an ABN is still active
If you have the number but do not know whether it is still live, put it in below. This checks the Australian Business Register directly and tells you the entity name, its status, and whether it is registered for GST.
That is not a valid ABN — check the digits and try again.
If the answer comes back cancelled
A cancelled ABN is not gone. If you are still entitled to one, you can usually get the same number reactivated rather than being issued a new one — which matters, because your invoicing history, your GST registration and anything a client has on file all point at the old number. The ATO also cancels ABNs itself when a business shows no activity across consecutive years, so plenty of people find theirs cancelled without ever having asked for it.
Reactivation is something you can do yourself through the ABR. If you would rather it was checked and lodged for you, we do that for $99 including GST, tax deductible.
Why your ABN might not appear under your business name
Sole trader ABNs are held against your legal name, not your trading name. If you registered "Coastline Painting" as a business name with ASIC, the ABN behind it is still recorded as your own name, with the business name listed underneath. Search yourself first, and check the business names listed on the result.
Common questions
How do I find my ABN number for free?
Search your legal name on ABN Lookup at abr.business.gov.au — it is a free public register and needs no login. If that does not narrow it down, sign in to ATO online services through myGov, where your own ABN is listed under the business section.
How do I find my ABN in myGov?
Sign in to myGov, open the linked ATO service, and look under the business area. Your ABN and its registration details appear there. If the ATO service is not linked to your myGov account yet, you will need to link it first, which requires identity details the ATO already holds for you.
Can I look up an ABN by name?
Yes — ABN Lookup searches by entity name, trading name and business name as well as by number. For a sole trader, search the person's legal name, because that is what the ABN is registered against.
Why can I not find my ABN on ABN Lookup?
The two common reasons are that you are searching a trading name that was never formally registered, or that the ABN has been cancelled and you are filtering to active records only. Cancelled ABNs stay visible on the register. Check the spelling of your legal name too — the register holds it exactly as the ATO does.
Is my ABN the same as my TFN?
No. Your TFN is private and identifies you to the ATO for tax; your ABN is public and identifies your business to everyone else. You are asked for your TFN when applying for an ABN so the ATO can match the application to you, but the two numbers are different and only the ABN goes on invoices.
ABN come back cancelled? We can reactivate it.
Usually the same number, usually the same business day. $99 inc GST, tax deductible.