- Set-off is the right to deduct an amount owed to you from an amount you owe to the same party, so that only the net difference actually changes hands (or so that a debt is reduced or…
- A set-off clause in a commercial contract usually addresses: - What can be set off against what — some clauses allow set-off only for amounts owed under the same contract; broader…
Two businesses owe each other money at the same time more often than people expect — a supplier owes a customer a credit for defective goods while the customer still owes the supplier for a separate invoice; a contractor owes a client back-charges for delayed work while the client still owes an outstanding progress payment. The instinct is obvious: just net it out. Whether a business can actually do that — legally, and without triggering its own breach — depends heavily on whether the contract contains a set-off clause and how it is worded.
This article explains what a right of set-off is, how a contractual set-off clause changes the default position, and the risks of withholding payment without one.
What "Set-Off" Means
Set-off is the right to deduct an amount owed to you from an amount you owe to the same party, so that only the net difference actually changes hands (or so that a debt is reduced or eliminated by the amount of a countervailing claim). It comes up constantly in ongoing commercial relationships where money tends to flow both directions.
There are a few different legal flavours of set-off recognized in Ontario, including rights that can arise independently of anything written in the contract, in narrow circumstances — but relying on an unwritten, general legal right of set-off is far less certain than having a clear contractual clause that spells out when and how it applies.
What a Contractual Set-Off Clause Typically Provides
A set-off clause in a commercial contract usually addresses:
- What can be set off against what — some clauses allow set-off only for amounts owed under the same contract; broader clauses allow set-off against amounts owed under any agreement between the same two parties.
- Whether the amount must be certain, or can be disputed — some clauses only permit set-off of a liquidated (fixed, undisputed) amount; others allow a party to withhold a reasonable estimate of a disputed claim pending resolution.
- Notice requirements — many clauses require the party exercising set-off to give notice of the amount and basis for the deduction before or when it withholds payment.
- Exclusions — some contracts expressly exclude the right of set-off altogether, particularly in finance and lending agreements, where a lender wants to be certain of receiving full, unconditional payments regardless of any dispute the borrower may raise separately.
Set-Off With a Clause vs. Without One
| With a clear set-off clause | Without one (relying on general legal principles) | |
|---|---|---|
| Certainty | High — the contract defines exactly what qualifies | Lower — depends on which narrow legal doctrine applies and whether the facts fit it |
| Scope | Can be broadened (any contract between the parties) or narrowed (same contract only) by agreement | Generally limited to closely connected claims arising from the same transaction or relationship |
| Disputed amounts | Can expressly allow withholding a good-faith estimate pending resolution | Withholding a disputed, unliquidated amount without a clear legal basis carries real risk of itself being a breach |
| Risk of getting it wrong | Lower — you can point to the contract's own terms | Higher — asserting set-off without a solid legal basis for a legally recognized deduction can be treated as your own default |
The Risk of Withholding Payment Without a Clear Right
Simply deciding not to pay an invoice because you believe the other side owes you money is not automatically legally protected, even if your underlying claim turns out to be valid. If a business withholds payment and it later turns out no valid right of set-off applied — the contract excluded it, the claim was too uncertain, or the amounts were not sufficiently connected — the business that withheld payment may itself be found in breach, potentially losing rights or remedies it would otherwise have had, and exposing itself to a claim for the full amount plus any resulting damages.
This is exactly why contracts of any real value should address set-off expressly, rather than leaving both sides to guess whether a general legal right applies to their situation.
Practical Steps Before Exercising a Set-Off Right
- Check whether your contract has a set-off clause, and read exactly what it allows — same contract only, or across the relationship generally; liquidated amounts only, or disputed claims too.
- Confirm your claim is genuinely valid and, ideally, quantified — the more certain and documented your counterclaim, the safer a set-off position is.
- Give notice before or when you withhold payment, in writing, explaining the basis and amount of the deduction — even if the clause does not strictly require it, this creates a record and reduces the chance of a dispute escalating unnecessarily.
- Do not assume set-off applies across unrelated contracts unless your clause specifically says so — the default, absent broad contractual language, tends to be narrower.
- Get legal advice before withholding a significant payment if there is any real doubt about whether set-off applies — the downside of guessing wrong (being found in breach yourself) is often worse than the amount in dispute.
Frequently asked questions
Can I withhold payment on one contract because the same company owes me money under a completely different contract?
Only if your contract's set-off clause is broad enough to allow that — many clauses limit set-off to amounts owed under the same agreement. Without express contractual language covering cross-contract set-off, relying on a general legal right to do this is uncertain and risky.
Do I need to prove my claim in court before I can set it off?
Not necessarily, if your contract's set-off clause allows deduction of a reasonable, good-faith estimate of a disputed amount pending resolution. Without that kind of clause, withholding an unproven, disputed amount is legally riskier, since the other side can argue no valid set-off right existed yet.
Can a contract completely eliminate the right to set off payments?
Yes — many finance, lending, and lease agreements specifically exclude set-off, often requiring payments to be made in full regardless of any dispute, with the paying party's remedy limited to pursuing its claim separately. If your contract has this kind of clause, withholding payment based on a countervailing claim can itself be a breach, even if your underlying claim has merit.
What should I do if the other side wrongly withholds payment from me, claiming a set-off right they don't actually have?
Review the contract's set-off clause (or lack of one) carefully, document the amount withheld and the stated reason, and get legal advice about your options, which may include formal notice of default or, if the amount is significant, a legal claim to recover the withheld payment.
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