Yes, you can use one ABN for multiple businesses in Australia. You can register as many business names as you like under the same ABN, as long as all of those businesses operate under the same legal structure. That's the key condition. If the structure changes, the ABN changes too.

This is a common setup for sole traders who run more than one venture, or for business owners who want to separate their brand identities without creating separate legal entities.

What "same legal structure" actually means

Your ABN is tied to your legal entity, not your trading name. The entity is the actual legal structure you operate under: sole trader, company, partnership, or trust.

If you're a sole trader running a lawn mowing business and you want to start a handyman service on the side, you can register both business names under your existing sole trader ABN. Both businesses are still you, the individual. Just trading under different names.

If you set up a company (a Pty Ltd) later, that's a different legal entity. You'd apply for a new ABN for the company, separate from your sole trader ABN.

Common examples:

Sole trader: You can register multiple business names through ASIC Connect, all tied to your individual ABN.

Company: A Pty Ltd gets one ABN. You can register multiple trading names under that company's ABN, but the company is the legal entity, not you personally.

Trust: The trust is its own entity with its own ABN. Business names can be registered to it.

Also Read: Can A Business Owner Have Multiple ABN Numbers?

How to register multiple business names under one ABN

Business names are registered through ASIC Connect. The process is the same whether it's your first business name or your fifth.

When you register, you enter your existing ABN. ASIC links the new business name to that ABN automatically. You can check all business names registered to an ABN using the ABN Lookup tool on the Australian Business Register.

Registration costs $42 for one year or $98 for three years (as of 2025; check ASIC for current fees).

Factors to Consider

While using one ABN for multiple businesses can simplify administration, there are factors to consider:

1. GST Registration: If the combined turnover of your businesses exceeds the GST threshold, you must register for GST.

2. Income Tax: Income from all businesses under the same ABN is combined for tax purposes.

3. Legal Liability: Businesses operating under the same ABN share legal and financial responsibility. Any legal or financial issues in one business could affect the others.

Tax and GST: what changes when you add more businesses

Income tax: All income earned under your ABN is reported on the same tax return, regardless of how many business names are attached. You report it as the one legal entity you are. If you're a sole trader, everything goes on your individual return.

GST: GST registration is based on the combined turnover of all businesses under your ABN. If your total income across all business names exceeds $75,000 in a financial year, you must register for GST, even if no single business individually hits that threshold.

Record keeping: Even though everything sits under one ABN, keeping separate records for each business name makes bookkeeping and tax time much simpler. Most accountants recommend it.

Also Read: Understanding Taxes For Australian Small Businesses

When you do need a new ABN

You need a separate ABN when the legal entity changes, not just the business name. The most common situations:

• You're operating as a sole trader and decide to incorporate as a Pty Ltd
• You join a partnership (the partnership gets its own ABN)
• You set up a trust to hold a new business
• One of your businesses has a different ownership structure to the others

If you're unsure, the ABR's ABN basics FAQ is the right starting point. For anything specific to your circumstances, speak to a registered accountant.

What Happens If One Business Gets Sued?

Running multiple businesses under one ABN means they share the same legal identity. A legal or financial issue in one business can affect your personal finances (as a sole trader) or the company as a whole. This is one reason some business owners choose to incorporate separate companies for businesses with different risk profiles, even if the admin is heavier.

Frequently Asked Questions

Can you have more than one ABN?

Yes, but only if you operate under more than one legal entity. Each legal entity (sole trader, company, trust, partnership) gets one ABN. You can't have two ABNs for the same sole trader identity.

Can you have multiple business names under one ABN?

Yes. You can register as many business names as you like under the same ABN through ASIC Connect, as long as they all operate under the same legal structure.

Do I need a separate ABN for each business?

No, not if all businesses share the same legal entity. You only need a new ABN when the legal structure is different, such as moving from a sole trader to a company.

Can I have 2 business names under 1 ABN?

Yes. There's no limit on how many business names you can register under one ABN.

Can I use the same ABN for a sole trader and a company?

No. A sole trader and a company are different legal entities. Each needs its own ABN.

What happens to my ABN if I change business structure?

You'll need to apply for a new ABN for the new structure. Your existing ABN stays active for the old entity until you cancel it.

Do I need separate insurance for each business name?

Business name registrations don't automatically come with separate insurance. If your businesses have different activities or risk profiles, it's worth reviewing whether your existing cover extends to all of them. Speak to a broker for advice specific to your situation.

Can I register a business name without an ABN?

No. ASIC requires an ABN or proof of entitlement to an ABN to register a business name in Australia.

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_{The information in this article about ABN registration and business structure is general in nature and drawn from publicly available sources. It does not constitute legal, tax, or financial advice. Always consult a registered accountant or adviser for advice specific to your situation.}