Do I Need an ABN When Registering a Company?

You don’t need an ABN to register a company in Australia, but you will need one before the company can legally trade. When registering a company, you lodge the registration with ASIC first and receive a 9-digit Australian Company Number (ACN). The 11-digit Australian Business Number (ABN) comes after that, once the company exists.

Here’s the part that trips people up. The ABN feels like the headline task, so founders rush at it, then find out the order matters and the company has to exist first. It’s the bit of starting a business everyone puts off, and it’s easy to get slightly wrong. Once you see the real sequence, though, it’s an afternoon of work, not a week.

Do you need an ABN to register a company?

No. You do not need an ABN to register a company, and you can’t get one until the company is registered anyway. The thing ASIC needs to bring your company into existence is a director ID and the registration application, not an ABN.

The confusion comes from treating the ABN as “the company”. It isn’t. A company is a separate legal entity created the moment ASIC registers it and issues the ACN. From that point the company can own assets, hold a bank account and sign contracts. What it can’t do cleanly is trade. To invoice customers, register for GST and deal with other businesses, the company needs an ABN as well.

So the honest answer to “do I need an ABN when registering a company” is: not to register it, but yes before you run it. Most founders want to trade straight away, which is why getting the ABN feels compulsory. In practice you’re doing two registrations in a row, with ASIC first and the ATO second.

What’s the difference between an ACN and an ABN?

This is the distinction that clears up most of the ABN-when-registering-a-company question. An ACN identifies your company. An ABN identifies your business for tax. A company ends up with both, issued by two different regulators, in a set order.

	ACN	ABN
Digits	9	11
Issued by	ASIC	ATO, via the Australian Business Register
Who gets one	Companies only	Any business: sole traders, partnerships, trusts and companies
When	The moment the company is registered	After the company exists, on a separate application
Cost	Part of the company registration fee	Free

Here’s a detail that surprises people: a company’s ABN is usually its ACN with two extra digits at the front. So an ACN of 123 456 789 typically becomes an ABN of 12 123 456 789. ASIC issues the 9-digit ACN when it registers the company, and the ATO builds the ABN from it. If you want the longer version, our guide on the difference between an ABN and an ACN walks through where each one shows up on your documents.

What order do you actually register everything in?

Order is where company setup goes wrong. The steps are simple, but they only work in one direction, and skipping ahead means you hit a wall and have to back up.

1. Get your director ID first. Every director must have one, and you need it before ASIC will register the company. You apply through Australian Business Registry Services, it’s free, and the verification can take a few days, so don’t leave it to the morning you want to register.
2. Register the company with ASIC. This creates the company and gives you the 9-digit ACN. You’ll choose a company name, set up shareholders and directors, and nominate a registered office. The ATO is blunt about the sequence: you need the ACN before you can get the ABN.
3. Apply for the ABN. With the ACN in hand, you apply to the ATO. Registering an ABN is free through the ABR, and most applications are approved on the spot.
4. Switch on GST and PAYG if you need them. You can do this in the same ABN application. Register for GST once you expect turnover above $75,000, and PAYG withholding before you pay your first employee.
5. Register a business name if you’re trading under anything other than your company name. “Acme Pty Ltd” trading as “Acme Coffee” needs a separate business name registration with ASIC. The ABN doesn’t do this for you.

Do it in this order and the whole thing is one smooth run. Try to grab the ABN before the company exists and you’ll be told to come back with an ACN. A good company registration service stitches the director ID prompt, the ACN and the ABN into a single flow, so you’re not bouncing between three government portals working out what unlocks what.

When should you get the ABN, and what happens if you trade without one?

Get the ABN before the company starts trading. Not before you register the company, but before the first invoice goes out. If you’ve set the company up to start earning next week, line up the ABN now so it’s ready when the work is.

Trading without one isn’t just untidy. When you don’t quote an ABN on an invoice, the business paying you is required to withhold 47% of the payment and send it to the ATO. That’s nearly half your money parked with the tax office until you sort the paperwork out. For a brand-new company chasing cash flow, that hurts.

Buying a shelf company changes the timing slightly. A shelf company is already registered and sitting on the shelf, so it has an ACN, but it usually won’t have an active ABN tied to your plans. Register for the ABN as soon as you take it over, and hold off trading until it lands. The old reason to buy a shelf company, speed, has mostly disappeared now that registering a new company takes minutes.

What we see in Lawpath consultations

The ABN-and-ACN mechanics are the easy part. The patterns that catch founders out show up later, and we see the same three on advisor calls again and again.

People treat the ABN as the finish line. They register the company, get the ABN, and assume they’re set for tax. Then turnover creeps past $75,000, or they take on a first employee, and they realise GST and PAYG were never switched on. Our accountants regularly take calls from businesses scrambling to backdate registrations they should have ticked at setup. The ABN is the gate, not the whole fence. GST and PAYG are separate, and the deadlines are tight: you have 21 days to register for GST once you cross the threshold.

Changing structure means a new ABN, not a transfer. A common assumption is that an existing sole-trader ABN moves across when you incorporate. It doesn’t. Switch from sole trader to company and you need a fresh ABN for the company, because the ABN belongs to the entity, and the company is a new entity. If you’re weighing up the move, our guides on whether you need a new ABN when switching to a company and on sole trader versus company structure are the two worth reading first.

The registration isn’t the end of the admin. Once the company exists, ASIC expects an annual review every year, and you have 28 days to tell ASIC if your details change. The same 28-day rule applies to keeping your ABN details current with the ABR. Advisors see late-notification penalties land on founders who thought registration day was the last form they’d ever file. It isn’t, but it’s manageable once it’s in your calendar.

Should you register the company yourself, buy a shelf company, or use a service?

Three real options, and the right one depends on how much of the admin you want to own.

Do it yourself through ASIC. You can register directly using ASIC’s Business Registration Service. ASIC’s fee to register a company is $611 for the 2025-26 financial year, and it’s indexed every 1 July, so check the current figure before you pay. This route is fine if you’re comfortable juggling the director ID, the ASIC application and the separate ABN step yourself.

Buy a shelf company. Worth considering in narrow cases, like bidding for a tender or applying for finance where a longer registration date reads as more established. For most new businesses it’s an unnecessary extra step, since the speed advantage that shelf companies once offered is gone.

Use a registration service. A service does the company and the ABN together, prompts you for the director ID, and stops you trading before the numbers are live. You’re paying to skip the portal-hopping and to not get the order wrong. For most founders setting up their first company, that’s the difference between an afternoon and a frustrating week.

Frequently asked questions

Does a company need an ABN?

A company needs an ABN to trade, invoice and register for GST, but not to exist. The company is created when ASIC registers it and issues the ACN. The ABN is a separate registration you apply for straight after, before the company starts doing business.

Does a company have to have an ABN?

A company carrying on a business in Australia needs an ABN. A dormant company that doesn’t trade can technically sit without one, but the moment it invoices or earns income, it needs an ABN. In real terms, any company you actually run will have both an ACN and an ABN.

Do you need an ABN to start a business?

If you’re running a business in Australia under any structure other than a hobby, you’ll need an ABN to operate. Sole traders, partnerships, trusts and companies all use one. For a company, you get the ABN after registering the company and receiving the ACN.

How long does it take to get an ABN for a company?

Most ABN applications are approved instantly once you have your ACN and your details check out. If the ATO needs to verify something, it can take up to 28 business days. Vague business activity descriptions and mismatched details are the usual cause of delays.

Is it free to register an ABN?

Yes. Registering an ABN through the Australian Business Register is free. If a website charges you for the ABN itself, you’re paying for a service fee, not the ABN. Registering the company with ASIC does cost money, currently $611 for 2025-26.

Do I need a new ABN if I change from sole trader to company?

Yes. You can’t carry your sole-trader ABN across to a company. The ABN belongs to the entity, and the company is a new entity, so it needs its own ABN. Cancel the old one once the company is up and running and the changeover is complete.

Can a company operate without an ABN?

Not in any practical sense. Without an ABN, businesses paying your company must withhold 47% of each payment, you can’t register for GST, and your invoices won’t meet ATO requirements. A company can exist without an ABN, but it can’t trade properly without one.

Do I need an ABN before I register the company?

No, and you can’t get one first anyway. The ACN from ASIC comes before the ABN from the ATO. Register the company, get the ACN, then apply for the ABN. Trying to do it the other way around won’t work.

If your head is spinning at the order of it all, that’s normal. Nobody starts a company already knowing what a director ID is or which number comes from which regulator. You’ve now got the sequence, which is more than most founders have on day one. The one thing to do next is start the company so the ACN and ABN can follow.

Ready to go? Register your company with Lawpath and we’ll handle the company and the ABN together, in the right order, so you can get back to the business you actually wanted to run.