Can You Use Someone Else’s ABN? Legal Risks and Safer Alternatives

If you’re running a small business in Australia, there’s a good chance you’ve been asked for an ABN at some point - by a supplier, a customer, a marketplace, a contractor, or an accountant.

And if you’re just getting started (or you’re in a rush to issue an invoice), it can be tempting to wonder: can I use someone else’s ABN?

Maybe it’s a family member’s ABN. Maybe it’s your business partner’s ABN. Maybe it’s the ABN of a company you “plan to set up soon”. Or maybe another business has offered to “run it through their ABN” to keep things simple.

In most cases, using someone else’s ABN is a big legal and tax risk. It can also create messy disputes about who actually provided the goods/services, who is responsible to the customer, and who owes what to the ATO.

Let’s walk through what an ABN is, when you can (and can’t) use another entity’s ABN, what the risks are, and the safer ways to structure your business properly from day one.

What An ABN Actually Does (And Why It Matters)

An Australian Business Number (ABN) is an 11-digit identifier that tells other businesses and government agencies who they’re dealing with for tax and business purposes.

It matters because an ABN is used for:

• Invoicing and identifying who is supplying goods/services
• GST (where applicable) and GST credits
• PAYG withholding rules (including the “no ABN withholding” rules)
• Business name registrations (which sit under an ABN)
• Contracts (which should match the correct legal entity)

Most importantly: an ABN is tied to a particular legal entity (for example, an individual as a sole trader, a partnership, a company, or a trustee for a trust). It’s not a general “permission slip” to do business.

If you’re unsure about the basics, it helps to understand the ABN setup and what it means to work under an ABN before you make decisions that could create liability.

So, Can I Use Someone Else’s ABN In Australia?

Most of the time, no - you shouldn’t use someone else’s ABN to invoice, sign up to platforms, or run your business sales.

When people ask, “can I use someone else’s ABN?”, they usually mean one of these scenarios:

• You want to invoice a client, but you don’t have an ABN yet
• You’re trading informally and want to “borrow” a family member’s ABN
• You’re operating under a friend’s or partner’s business to “keep it simple”
• A business offers to “put you through their books” and pay you

In those scenarios, using another person’s ABN can quickly become misleading (to customers), inaccurate (for tax reporting), and dangerous (for legal responsibility).

When It Might Be Legitimate

There are limited situations where another entity’s ABN is used, and it’s still lawful, but the key is this:

The ABN on the invoice must belong to the entity that is actually making the supply.

For example:

• You are an employee and your employer invoices customers using the employer’s ABN (normal)
• You are a contractor engaged by a company, and the company invoices the end customer because the company is the supplier (you invoice the company, not the end customer)
• You are genuinely operating through a company/trust (e.g. you are the director of a company and the company is the entity trading) and the company’s ABN is used

The difference is not “whose ABN you have access to” - it’s who the supplier is in the legal sense, and what your contracts and payment flows actually show.

What Are The Legal And Tax Risks Of Using Someone Else’s ABN?

This section is general information only and isn’t tax advice. Tax outcomes can vary depending on your structure and circumstances, so it’s a good idea to speak with your accountant or a registered tax agent about your specific situation.

Even if everyone involved has good intentions, “borrowing” an ABN often creates a mismatch between:

• who the customer thinks they’re dealing with
• who is legally responsible for the job
• who reports the income
• who pays GST (if applicable)
• who carries the risk if something goes wrong

Here are the key risks small business owners should understand.

1. You Can Create A False Or Misleading Paper Trail

If you do work, but you invoice using someone else’s ABN, your documents may suggest that they provided the services (not you).

That can become a serious issue if there’s a customer complaint, refund demand, warranty claim, or dispute about what was promised.

It can also increase your risk under the Australian Consumer Law (ACL), particularly around representations about who is supplying goods/services and who is responsible for remedies. If you’re selling to consumers, your customer-facing terms and processes matter a lot. Clear contracts and compliant customer terms can help, but they generally can’t fix a fundamentally incorrect supplier identity.

2. The “Owner” Of The ABN Becomes The One On The Hook

In many disputes, the customer will pursue the entity named on the invoice and contract.

So if you use someone else’s ABN:

• they may be treated as the supplier
• they may be responsible for refunds/rectification
• they may be the party sued if something goes wrong

That can destroy relationships quickly, especially if the “ABN owner” didn’t truly control the job.

3. ATO and GST Reporting Can Get Messy Fast

If income is earned under someone else’s ABN, it may be reported as their business income, not yours.

That can cause problems such as:

• incorrect income tax reporting
• GST being charged or not charged incorrectly
• confusion about deductions (who can claim business expenses?)
• bookkeeping and BAS errors (if GST-registered)

Even if you “sort it out later”, it can be very difficult to unwind months of invoices and payments that were made under the wrong entity details.

4. You Can Trigger “No ABN Withholding” Issues

There are rules that may require a payer to withhold tax if a supplier doesn’t quote an ABN (subject to exceptions).

Using someone else’s ABN may look like you’re quoting an ABN, but if the supplier details don’t match reality, it can still create withholding and compliance issues.

If you’re dealing with suppliers or contractors, it’s worth having internal processes (and contracts) that clearly set out who invoices whom, and under what details, so you don’t drift into non-compliance.

5. It Can Look Like You’re Hiding The Real Business

Sometimes, businesses use another ABN because they’re trying to avoid:

• tax obligations
• debt recovery exposure
• platform bans or restrictions
• proper licensing or insurance requirements

Even if you’re not doing anything deliberately wrong, it can look suspicious to banks, platforms, suppliers, or regulators if your invoices and branding don’t match the legal entity actually trading.

And in disputes, this can undermine your credibility quickly.

Common Scenarios Small Businesses Ask About (And What To Do Instead)

Let’s look at the situations we see most often and the safer way to handle each.

“I Haven’t Set Up My ABN Yet - Can I Invoice Under My Partner’s ABN Just Once?”

This is one of the most common reasons people search for can I use someone else’s ABN.

But “just once” is still risky, because it creates a record that your partner was the supplier. That affects tax reporting and liability for that job.

Safer alternatives:

• Delay invoicing until your ABN is active (where possible)
• Structure the job so your partner’s entity genuinely contracts with the customer and subcontracts the work to you (with proper documentation)
• If you’re planning to trade through a company, set it up first so the company is the supplier from day one

If you are planning to trade through a company, you may also need a Company Constitution so the business has clear internal rules, especially if there is more than one owner.

“I’m Helping A Friend’s Business - Can I Use Their ABN For My Side Work?”

Usually, no. If you are doing your own separate work, you should invoice under your own ABN and have a clear client contract in your name (or your entity’s name).

Otherwise, customers may treat your friend’s business as the supplier, and your friend may end up responsible for your work.

Safer alternatives:

• Get your own ABN and keep your invoicing clean
• If you’re actually working inside their business, document it properly as an employment relationship or contractor arrangement

If you are engaging someone (or being engaged) as a contractor, the paperwork matters. A properly drafted Contractors Agreement can help clarify invoicing, responsibility, IP ownership, and liability allocation.

“We’re Starting A Business Together - Can We Just Use One Person’s ABN?”

This depends on what you’re actually doing.

If one person is truly the sole trader and the other person is simply helping (as an employee or contractor), then yes, the sole trader’s ABN can be the trading ABN.

But if you’re genuinely co-owning the business, sharing profits, and making joint decisions, using one person’s ABN can create confusion and disputes later about:

• who owns the business
• who owns the customer list and brand
• who is entitled to profits
• what happens if one person wants to exit

Safer alternatives:

• Form a partnership (and make sure your registration and agreements reflect that)
• Set up a company (often preferred for risk management and growth)
• Put a written agreement in place early (before money starts moving)

If you’re building a business with someone else, a Shareholders Agreement (for a company) or a partnership agreement can save you from a lot of pain later.

“A Business Offered To Invoice The Customer Under Their ABN And Pay Me”

This arrangement can be legitimate, but it needs to be structured properly.

For example, if the business truly contracts with the customer and is responsible for delivering the service, then they are the supplier and can invoice under their ABN. You would then invoice that business for your work (as a subcontractor), and the arrangement should be documented.

However, if the business is only “renting out” their ABN while you do everything else (marketing, quoting, contracting, delivering, handling complaints), the arrangement may not reflect reality and can expose both parties to liability and tax issues.

Tip: In these scenarios, clear contract documentation is essential, including who owns the customer relationship, who carries insurance, and who is liable for defects or disputes.

Safer Alternatives To Using Someone Else’s ABN

If your goal is “I want to trade quickly and legally”, there are better options than borrowing an ABN.

Here are practical alternatives that usually work far better for small businesses.

1. Get Your Own ABN (And Keep Your Invoicing Clean)

If you’re running your own business activities, having your own ABN is often the simplest way to keep:

• your contracts consistent
• your tax reporting accurate
• your customer relationships clear

It also helps you avoid future disputes about who “really” did the work.

2. Choose The Right Business Structure Early

One reason people try to use someone else’s ABN is because they’re unsure what structure to pick, or they want to delay the admin.

But structure decisions affect your risk and growth. Common options include:

• Sole trader: simple and low-cost, but you are personally liable for business debts and claims
• Company: a separate legal entity that can offer limited liability protection (but has more setup and ongoing compliance)
• Partnership: can work for co-founders, but needs careful planning because each partner can create liability for the others
• Trust: often used for asset protection or investment structures, but needs proper legal and accounting advice

If you’re setting up a company, it’s also important to ensure the company’s internal documents and ownership arrangements are properly documented (especially where there’s more than one founder).

3. Use A Contractor Or Employment Model (Where It Fits The Reality)

If you are doing work inside another business, it may be cleaner to formalise the relationship as either:

• an employment arrangement (they control the work and take responsibility), or
• a contractor arrangement (you invoice them under your ABN and they invoice the customer)

The key is making sure your arrangement matches what’s actually happening day-to-day.

If you are hiring team members in your own business, it’s worth having a solid Employment Contract in place so you’re not relying on informal agreements that can create risk later.

4. Put Proper Terms In Place With Customers

If your ABN/entity details are unclear, customer disputes become harder to manage.

Even if you’re a small operator, you should aim to have a clear customer agreement or set of terms that explains:

• who the supplier is (your correct legal name and ABN)
• what is included (and excluded) in your services
• payment terms and late payment rights
• timeframes and variations
• limits on liability (where legally allowed)

Having proper terms is also part of good consumer law compliance, especially if you deal with consumers and need to be clear about refunds, cancellations, and representations.

How To Reduce Risk If Someone Else’s ABN Has Already Been Used

If you’ve already used someone else’s ABN (even unintentionally), you’re not alone - many small businesses do this early on before they understand the consequences.

The key is to tidy it up quickly and avoid repeating it.

Some practical next steps may include:

• Stop issuing invoices under the other ABN immediately
• Work out who was the supplier in each transaction (and what your paperwork shows)
• Speak with your accountant or a registered tax agent about how the income should be reported and whether invoices need to be reissued
• Review your customer contracts and communications to ensure customers weren’t misled about who they were contracting with
• Put proper agreements in place between you and the ABN owner if you’re continuing to work together

If the arrangement was ongoing, it’s often worth getting legal help to untangle responsibility and prevent disputes. In our experience, the earlier you fix these issues, the less expensive and stressful it is.

Key Takeaways

• In most cases, the answer to can I use someone else’s ABN is no - the ABN on the invoice should match the entity that is actually supplying the goods or services.
• Using someone else’s ABN can create major problems with tax reporting, GST, liability, and customer disputes, even if you had good intentions.
• If the ABN owner is named on the invoice or contract, they may end up “on the hook” legally if something goes wrong.
• Safer alternatives include getting your own ABN, choosing the right business structure early, and documenting contractor/employment relationships properly.
• Clean contracts and clear customer terms reduce risk and make it easier to resolve disputes if they arise.
• If you’ve already used someone else’s ABN, it’s best to stop, get accounting advice on reporting, and formalise the correct structure going forward.

If you’d like help setting up the right structure and contracts so your business can trade confidently under the correct ABN, you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no-obligations chat.