ABN vs ACN: What's the Difference and Which Do You Need — 2026 AU Guide
An ABN (Australian Business Number) is an 11-digit identifier issued by the ATO that any business entity can hold, while an ACN (Australian Company Number) is a 9-digit number issued by ASIC exclusively to registered companies. Most sole traders and partnerships need only an ABN, whereas anyone operating a proprietary limited (Pty Ltd) company must obtain both an ACN and an ABN.
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What Is an ABN and Who Needs One?
An Australian Business Number is the cornerstone identifier for nearly every business operating in Australia. The ATO administers the ABN register, and as of 2025 there were approximately 9.2 million active ABNs on the Australian Business Register — a figure that reflects the sheer breadth of business activity across the country, from one-person freelance operations to large partnerships (Australian Business Register, 2025).
You are entitled to apply for an ABN if you are carrying on an enterprise in Australia. That includes:
- Sole traders — the most common structure for tradies, consultants, and freelancers - Partnerships — two or more people running a business together - Trusts — a trustee carrying on business on behalf of beneficiaries - Companies — registered under the Corporations Act 2001 - Non-profit organisations and charities
Critically, having an ABN lets you quote your number on invoices, claim goods and services tax (GST) credits if you're registered for GST, avoid pay-as-you-go (PAYG) withholding from business payments, and access a range of government services. Applying for an ABN through the Australian Business Register is free, though many Australians use a registration service to handle the paperwork correctly and avoid common errors.
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What Is an ACN and Who Needs One?
An Australian Company Number is a unique 9-digit identifier issued by the Australian Securities and Investments Commission (ASIC) when a company is registered under the Corporations Act 2001. Unlike an ABN, an ACN is only available to — and required by — companies. It cannot be held by a sole trader, partnership, or trust in its own right.
Every proprietary limited company (Pty Ltd) and public company in Australia must display its ACN on all public documents, including contracts, invoices, and official correspondence — unless the company's ABN is used instead and the ACN is included in the ABN. The ACN serves as ASIC's internal tracking mechanism, allowing regulators, creditors, and consumers to look up a company's filing history, officeholder details, and financial disclosures on the ASIC Connect portal.
ASIC reported that there were more than 3.6 million companies registered in Australia as at June 2025 (ASIC Annual Report, 2025). Each one holds both an ACN and an ABN.
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Key Differences Between an ABN and an ACN
The two numbers are frequently confused, but they serve distinct regulatory purposes. Here is a side-by-side comparison of the most important distinctions:
| Feature | ABN | ACN | |---|---|---| | Issuing body | ATO / Australian Business Register | ASIC | | Length | 11 digits | 9 digits | | Who can hold it | Any business entity | Companies only | | Cost to obtain | Free | Included in company registration fee | | Primary purpose | Tax and business identity | Company identification and compliance | | Required to register for GST? | Yes | No (ABN required instead) | | Displayed on invoices? | Yes (preferred) | Can substitute if ABN unavailable |The simplest rule of thumb: if you are not registering a company, you need an ABN. If you are registering a company, you will receive an ACN from ASIC first, and then apply for an ABN using that ACN.
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How Much Does It Cost to Get an ABN or Register a Company in 2026?
Obtaining an ABN directly through the Australian Business Register is free. Company registration with ASIC, however, attracts a government fee. As at 2026, ASIC charges $597 AUD to register a proprietary company — a fee updated annually, so always verify the current rate on the ASIC website before proceeding.
Many business owners use a third-party registration service to bundle company registration, ABN application, and optional extras like GST registration or a registered agent service. Prices vary considerably:
| Service Option | What's Included | Approximate 2026 Cost (AUD) | |---|---|---| | DIY via ASIC + ATO | ACN registration, ABN application (self-managed) | $597 (ASIC fee only) | | Basic registration service | ACN, ABN, registered agent address | $697 – $850 all-in | | Full-service package | ACN, ABN, GST registration, TFN application, share structure setup, company constitution | $950 – $1,400 all-in |For a detailed breakdown of what you'll pay across leading providers, see our cost guide. If you're based in New South Wales, our roundup of the best company registration services in Sydney can help you shortlist reputable local and online options.
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Which Structure — and Which Number — Is Right for Your Business?
Choosing between an ABN-only setup and a full company registration (ACN + ABN) depends on several factors:
Go ABN-only (sole trader or partnership) if: - You are testing a business idea or freelancing part-time - Your annual turnover is expected to remain below $150,000 - You want minimal compliance obligations and record-keeping - You are comfortable with unlimited personal liability Register a company (ACN + ABN) if: - You want limited liability protection — your personal assets are shielded from business debts - You plan to take on investors or issue shares - Your accountant has advised a company structure for tax planning purposes - You need to build credibility with larger corporate clients who prefer contracting with a Pty LtdA trust structure is another option for asset protection and income distribution, but a trust still needs a trustee — and if that trustee is a company, you're back to needing both an ACN and an ABN. Our methodology explains how we evaluate registration services across all major Australian business structures.
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How to Apply: Step-by-Step Overview
To get an ABN only (sole trader/partnership/trust): 1. Visit the Australian Business Register at abr.gov.au 2. Complete the online application (takes roughly 15–30 minutes) 3. Your ABN is issued instantly in most cases; some applications are referred for review and may take up to 28 days To register a company (ACN + ABN): 1. Choose a company name and confirm availability via ASIC Connect 2. Lodge Form 201 (Application for Registration as an Australian Company) via ASIC or a registered agent 3. ASIC issues your ACN (typically within 24 hours for online applications) 4. Apply for your ABN via abr.gov.au using your new ACN 5. Optionally register for GST (mandatory if turnover exceeds $75,000 per year), PAYG withholding, and other tax obligationsUsing a reputable registration service can compress steps 2–5 into a single workflow, reducing the chance of errors on official documents.
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FAQ
Q: Can I use my ACN instead of my ABN on invoices? A: Yes, but only in limited circumstances. If your company's ABN contains your ACN as its last nine digits (which it always does), displaying your ABN satisfies the requirement to show your ACN. Most accountants recommend always quoting your 11-digit ABN on invoices as it conveys more information and is universally recognised for GST purposes. Q: Is it possible to have an ABN without an ACN? A: Absolutely. Sole traders, partnerships, and trusts (where the trustee is an individual, not a company) hold an ABN but never receive an ACN. An ACN is exclusively issued to registered companies. Q: How long does it take to get an ABN in 2026? A: Most ABN applications lodged online through the Australian Business Register are processed instantly. Applications that require manual review — for example, where residency or identity details need verification — can take up to 28 days. Using a registration service does not speed up ATO processing but can reduce errors that trigger manual review. Q: What happens if I operate without an ABN? A: If you fail to quote an ABN on an invoice to another business, the paying business is legally required to withhold 47% of the payment and remit it to the ATO — the top marginal tax rate as at 2026. You can reclaim withheld amounts by lodging a tax return, but the cash flow impact can be significant. Obtaining an ABN costs nothing and takes minutes, so there is little reason to delay.---
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