- A counterclaim is a claim you, as the defendant, bring against the plaintiff, filed and heard as part of the same court file.
- Counterclaims work best when your claim against the plaintiff is genuinely related to the same relationship or dispute — for example: - You're sued for an unpaid invoice, but the other…
- Prepare your counterclaim document setting out what you're claiming and why, in the same way a Plaintiff's Claim would be drafted.
Being sued doesn't always mean you're only on the defence. If the person or business suing you also owes you money — for a related debt, damage they caused, or a separate part of the same falling-out — Ontario's Small Claims Court lets you bring your own claim back at them within the same case. This is called a counterclaim small claims court ontario proceeding, and it can save you the time and cost of starting an entirely separate lawsuit.
What a Counterclaim Is — and Isn't
A counterclaim is a claim you, as the defendant, bring against the plaintiff, filed and heard as part of the same court file. It's not the same as simply disputing what the plaintiff says — a defence tells the court why you shouldn't have to pay them; a counterclaim tells the court why they should have to pay you.
When a Counterclaim Makes Sense
Counterclaims work best when your claim against the plaintiff is genuinely related to the same relationship or dispute — for example:
- You're sued for an unpaid invoice, but the other side also owes you money on a separate job
- A contractor sues for the balance of a contract, but you have a legitimate claim for deficient work
- A former business partner sues over one issue, while you have a claim arising from the same falling-out
If your claim against the plaintiff is completely unrelated, a separate action may be more appropriate — though nothing stops you from counterclaiming even then, subject to the court's own case-management discretion.
How to File a Counterclaim
- Prepare your counterclaim document setting out what you're claiming and why, in the same way a Plaintiff's Claim would be drafted.
- File it with the Small Claims Court handling the original claim, generally alongside or shortly after your Defence.
- Serve the plaintiff with your counterclaim so they have formal notice and an opportunity to respond.
- The plaintiff can respond to your counterclaim much like a defendant would respond to an original claim.
- Both claims proceed together — through the same settlement conference and, if needed, the same trial.
The Monetary Limit Applies to Counterclaims Too
Small Claims Court's monetary jurisdiction — a meaningful $50,000 as of mid-2026, exclusive of costs and interest, though this figure is adjusted periodically so verify it before relying on it — applies to counterclaims the same way it applies to the original claim. If your counterclaim would exceed that limit, it may not be able to proceed within Small Claims Court, and you may need to consider whether a different court is the right venue for that portion.
What Happens at the Settlement Conference
Once a counterclaim is filed, the mandatory settlement conference that Small Claims Court requires in every defended case typically addresses both the original claim and the counterclaim together. This is often a practical advantage — it gives everyone a chance to discuss the whole dispute, not just one side of it, and can make a global settlement more realistic than resolving the pieces separately.
Counterclaim vs. Starting a Separate Action
| Consideration | Counterclaim (Same Case) | Separate Lawsuit |
|---|---|---|
| Extra filing needed | One additional document, same file | An entirely new claim and court fee |
| Timing | Resolved alongside the original claim | Proceeds on its own schedule |
| Settlement conference | Covers both claims together | Separate proceedings, separate conferences |
| Best suited for | Claims connected to the same dispute | Claims unrelated to the original lawsuit |
Frequently asked questions
Can I counterclaim for more than the plaintiff is suing me for?
Yes, within the Small Claims Court monetary limit. Your counterclaim doesn't need to match or be smaller than the original claim amount.
Does filing a counterclaim delay the original claim?
It can add a modest procedural step, since the plaintiff needs an opportunity to respond, but both claims are generally managed together rather than one waiting on the other to fully finish.
What if I want to claim against someone who isn't already part of the case?
A counterclaim is specifically against the plaintiff who sued you. If you need to bring in someone else entirely — a supplier or subcontractor, for instance — that typically involves a different procedural step rather than a counterclaim.
Can I still counterclaim after I've already filed my defence?
Often yes, though it's best to raise it as early as possible. Waiting too long can complicate scheduling and may require the court's permission depending on how far the case has progressed.
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