What Is a Set-Off? Legal Meaning and When to Use It

When you run a small business, it’s common to have ongoing relationships where money flows both ways. You might supply goods to a customer who also provides services back to you. Or you might have a supplier you pay regularly, but they also owe you a refund, credit, or damages.

That’s where set-off comes in.

If you’ve ever wondered what a set-off is in a business context, it’s essentially a way to net out what’s owed between two parties, so only the balance is paid. Done properly, it can be a practical tool that reduces disputes and avoids “cash going in circles”. Done poorly, it can trigger serious problems, including breach of contract claims, debt recovery issues, or (in an insolvency scenario) costly challenges from an administrator or liquidator.

Below, we’ll walk you through what set-off means in Australia, when you can use it, what to watch out for, and how to build clear set-off rights into your contracts so you can run your business with more certainty.

This article is general information only and doesn’t take into account your specific circumstances. It isn’t legal advice.

What Is a Set-Off (And Why Do Small Businesses Use It)?

At a practical level, a set-off is when you reduce the amount you pay someone because they owe you money too.

In other words, instead of Party A paying Party B $10,000, and Party B paying Party A $3,000, you “set off” the $3,000 and Party A pays Party B the net amount of $7,000.

Small businesses use set-off because it can:

• Simplify payments when you have mutual dealings
• Improve cash flow by keeping money in your business rather than paying first and chasing later
• Reduce debt recovery costs and admin
• Encourage faster resolution of disputes about invoices, credits, or defects

But set-off isn’t just a casual accounting trick. It’s a legal concept, and whether you can actually rely on it depends on the contract, the type of claim, and the circumstances.

Set-Off vs A “Discount” vs A “Withholding”

These ideas can look similar in day-to-day business, but legally they’re not the same:

• Discount: an agreed price reduction (usually agreed before payment is due).
• Withholding: refusing to pay (or delaying payment) because you’re unhappy or waiting for something else to happen.
• Set-off: paying less because you assert the other party owes you an amount that should be credited against your debt.

A well-drafted contract can make set-off rights clear and reduce arguments about whether you were “allowed” to pay less.

What Types Of Set-Off Apply In Australia?

In Australia, “set-off” can arise in a few ways. The key point is that not all set-offs are treated equally, and you should be careful about assuming you can always do it just because it feels fair.

Contractual Set-Off (The One You Can Plan For)

This is the most common type for small businesses. A contractual set-off is where your contract (or terms and conditions) expressly says you can set off amounts the other party owes you against amounts you owe them.

This is usually included in:

• terms of trade / terms of sale
• customer contracts for ongoing services
• supply agreements
• construction or project agreements

If you have strong written terms (for example, in your Terms of Trade), you can often reduce disputes because everyone knows the rules from the start.

Equitable Set-Off (Often Used In Disputes)

Equitable set-off comes from principles of fairness developed by the courts.

It may apply where:

• you owe the other party money (for example, an invoice is due), and
• you have a closely connected claim against them (for example, you suffered loss because their goods or services were defective).

Equitable set-off is not something you want to rely on casually. It can be complex and fact-specific, and it often becomes a dispute about whether the claims are sufficiently connected.

Legal Set-Off (Mutual Debts In The Right Form)

Legal set-off (sometimes called “set-off at law”) generally requires that there are mutual debts between the parties that are due and payable in a way the law recognises for set-off.

In practical terms, it’s often narrower than what business owners expect. That’s why contractual set-off clauses are so valuable: they let you define your set-off rights clearly, rather than relying on technical rules later.

When Can Your Business Actually Use Set-Off?

Even if you understand set-off in theory, the real question is: when can you safely use it without creating a bigger legal problem?

Here are common small business scenarios where set-off might come up.

1. Customer Disputes An Invoice Because Of Defective Goods Or Services

Example: You install equipment for a customer. They claim it doesn’t work properly and they’ve incurred costs fixing it. They refuse to pay your invoice in full and say they’re “setting off” their losses.

Whether they can do that depends on:

• what your contract says about set-off
• whether they’ve actually established a valid claim
• consumer law obligations (if applicable)
• the connection between their claim and your invoice

If you sell to consumers (or even small businesses that qualify as “consumers” under Australian Consumer Law in some situations), you also need to consider your obligations around acceptable quality, remedies and refunds. This is where it helps to understand the consumer guarantees landscape.

2. You Have A Credit Note Or Refund Owed By A Supplier

Example: Your supplier issued you a credit note for returned stock. You also owe them for a new order. Set-off can be a practical way to pay only the net amount.

This is usually straightforward if both sides agree, but it’s still best practice to:

• confirm the credit is valid and approved
• document the netting arrangement in writing (even by email)
• check your contract terms for set-off restrictions

3. Ongoing Service Relationships (Mutual Invoices)

Example: You manage marketing for a client, and they also provide IT support to your business. Each month both parties invoice each other. Set-off can simplify payment administration, but it needs structure.

In these situations, having a solid written service arrangement helps you manage payment mechanics, disputes, and remedies. Many businesses deal with this through a tailored Service Agreement and consistent invoicing processes.

4. Employment-Related Deductions (Be Very Careful)

Sometimes businesses ask about “set-off” in the context of deducting money from wages (for example, to recover an overpayment or pay for damaged equipment).

This is a higher-risk area because wage deductions are heavily regulated and you generally can’t simply “set off” amounts against wages unless you meet strict requirements (including written authorisation, and award/enterprise agreement considerations). The rules can also be technical, so it’s worth getting advice before making any deductions.

If you employ staff, getting your documentation right from the start (including an Employment Contract) can reduce the chance of disputes about pay, deductions, and entitlements later.

What Are The Risks If You Get Set-Off Wrong?

Set-off is useful, but it can also create disputes quickly if you apply it without a clear legal basis.

Some common risks include:

Breach Of Contract Claims

Many contracts say invoices must be paid in full within a certain time and may also include wording like “payment must be made without set-off”.

If your contract prohibits set-off and you pay less anyway, you may be:

• in breach of the payment clause
• triggering default interest
• exposing yourself to debt recovery action (and sometimes legal costs)

Cash Flow And Relationship Damage

Even where you may have a legitimate claim, aggressively setting off can damage a commercial relationship. It can also cause a “payment spiral” where neither party pays, and both claims sit unresolved.

A practical approach is to separate two issues:

• Payment discipline: invoices are paid on time unless there’s a genuine dispute process
• Dispute resolution: claims are handled through an agreed process (variation, rectification, credit note, etc.)

Insolvency Complications

Set-off can become especially complex if one party becomes insolvent (for example, enters voluntary administration or liquidation). Insolvency laws may affect what can be set off, when it can be set off, and how it must be calculated, and transactions close to insolvency can be scrutinised. Because the rules are technical and very fact-dependent, it’s a good idea to get advice early if insolvency is on the table.

If you’re trading with a business showing signs of financial distress, it’s worth tightening your terms and thinking strategically about credit exposure (including whether security interests might be relevant in your industry). For asset-heavy supply arrangements, businesses sometimes also consider PPSR registration mechanics, such as a PPSR strategy, depending on what’s being supplied and on what terms.

How Do You Draft A Good Set-Off Clause In Your Business Contracts?

If you want set-off to work as a practical tool (not a legal headache), you should build it into your contracts clearly.

A set-off clause is often part of your broader payment and dispute framework, such as:

• when invoices are due
• how you handle disputed invoices
• late payment interest
• rights to suspend services for non-payment
• limitations on liability

There isn’t a one-size-fits-all clause. The “right” approach depends on whether you are usually the party being paid, the party paying, or both (as in ongoing supply relationships).

Option A: Allow Set-Off (Common For Buyers)

If you’re often in the buyer/customer position, you may want terms that allow you to set off amounts owed to you (for example, credits or damages) against invoices you receive.

Key issues to define include:

• what types of amounts can be set off (credits only, or also damages/claims?)
• whether the set-off must be agreed or can be claimed unilaterally
• how notice must be given (email, written notice, within a certain timeframe)

Option B: Prohibit Set-Off (Common For Sellers)

If you’re usually the seller/service provider, you may want to prohibit set-off so you can protect predictable cash flow.

This is common where you:

• operate on tight margins
• need certainty to pay staff and suppliers
• see customers frequently “short pay” invoices without proper basis

If you prohibit set-off, you should also include a clear dispute resolution process so customers still have a fair and structured way to raise issues without simply withholding payment.

Option C: Limited Set-Off With Guardrails (Often The Most Practical)

Many small businesses do best with a middle ground approach, such as:

• set-off is only allowed for agreed credits (like approved returns or credit notes)
• set-off is not allowed for unproven claims or allegations
• set-off requires written notice and supporting documentation

This reduces abuse of set-off while still giving you flexibility to handle legitimate adjustments efficiently.

Don’t Forget The Rest Of Your Contract Ecosystem

Set-off clauses tend to work best when your broader legal documents are consistent, including:

• Customer terms (payment, delivery, disputes)
• Supplier terms (returns, credits, risk transfer)
• Company governance documents if you have multiple decision-makers approving credits and write-offs

If you run a company (rather than a sole trader structure), having a clear Company Constitution can help set internal rules around approvals and decision-making, especially as your team grows.

Key Takeaways

• What is a set-off? It’s a legal mechanism to net out mutual amounts owed between two parties, so only the balance is paid.
• Set-off can arise through contractual set-off (best for certainty), or through legal/equitable principles (often more complex and dispute-prone).
• Before using set-off, check whether your contract allows it, limits it, or prohibits it, because an unauthorised set-off can amount to breach of contract.
• Set-off is common in invoicing disputes, credit notes, and ongoing service relationships, but it should be handled with clear documentation and a consistent process.
• For small businesses, the best protection usually comes from well-drafted terms that clarify when set-off is permitted, how notice must be given, and what can be set off.
• If set-off intersects with high-risk areas (like employment deductions or insolvency situations), getting advice early can help you avoid costly mistakes.

If you’d like help setting up set-off clauses in your contracts or tightening your payment terms, you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no-obligations chat.

Official Sources to Check

Rules and regulator guidance can change. Check the current official material most relevant to this issue before relying on the article:

• ACCC: Contracts and unfair contract terms