Not legal advice; Ontario information as of October 4, 2026. Sources: Ontario's Guide to Procedures in Small Claims Court: Replying to a claim and Making a claim (both pages last updated July 2, 2026), and the Ontario Courts page on the defendant's claim.
Defence or defendant's claim: which one is it?
People often mix these up because both come after you are served. They do different jobs, and you can do both in the same case. The Ontario Courts page is direct about it: a defendant's claim is not the same as a defence.
| Defence (Form 9A) | Defendant's claim (Form 10A) | |
|---|---|---|
| What it does | Responds to the plaintiff's claim: dispute it, admit it, or admit part of it. | Makes your own claim: you say the plaintiff, another person, or both owe you. |
| Who it is against | It answers the plaintiff. | The plaintiff and/or another person you believe is responsible. |
| Time limit | 20 calendar days from being served. | 20 days after you file your defence, unless the court allows later on a motion. |
| Your role | Defendant. | The guide says you are “the plaintiff” in this new claim. |
Our walkthrough of the Form 9A defence covers the first column in detail.
The two clocks
A defendant's claim runs on two separate deadlines, and they start at different moments.
- Clock 1 — issue it. File Form 10A within 20 calendar days after you file your defence. The 20 days run from the day you filed, not from the day you were served.
- Clock 2 — serve it. Once the claim is issued, the Ontario Courts page says it must be served within 6 months. Ontario's guide says the same 6-month rule for claims generally.
If you miss the first clock, the guide says you can make a motion and ask the court to allow you to file later. That is a request, not a right, so treat 20 days as firm.
Who you can claim against
The Ontario Courts page says you can bring a defendant's claim against the plaintiff, against another person, or both, if you believe the plaintiff owes you money or someone else is responsible for the loss the plaintiff is claiming. The second case is the one people overlook: if you think a different person caused the problem, a defendant's claim is how you bring them into the same case.
If you are claiming against more than one party, the guide says to list one party on the main form and attach Additional Parties (Form 1A) as page 2.
What goes in the claim
A defendant's claim is built like a plaintiff's claim. Ontario's guide says it must explain who you are, who you are claiming against, what happened, and what you are asking for. In practice that means:
- Full names and addresses of everyone involved.
- The amount you are claiming and the pre-judgment interest rate, if you are claiming interest.
- A clear account of events with dates and locations.
- Supporting documents attached to the claim.
Our Form 7A walkthrough goes through these pieces step by step, since the same rules apply.
Serving it
The guide says a claim can be served by you, a friend, a business associate or a private process server, with one Affidavit of Service (Form 8A) completed for each person served (see our Form 8A walkthrough). The Ontario Courts page adds that a plaintiff's claim must be served personally, even if the person is outside Ontario, unless the court allows another method. Because the guide treats you as the plaintiff on Form 10A, plan on personal service and confirm with the court if you want to try another route.
You can file through the Small Claims Court Submissions Online portal, or in person. A filing fee applies at the time of filing; neither the guide nor this page sets out the current amount, so check with the court.
Mistakes to avoid
- Counting from the wrong day. The 20 days start when you file your defence.
- Treating it as part of the defence. It is its own form, filed and served separately.
- Forgetting the second clock. Issuing the claim is not the finish line; it still has to be served within 6 months.
- Skipping the underlying limits. A claim of your own has its own limitation period, which is separate from these procedural deadlines.
For the full path from first filing to a hearing, see our Small Claims Court process guide.
Frequently asked questions
What is the deadline for a defendant's claim? 20 days after you file your defence, unless the court allows later on a motion.
Is it the same as a defence? No. A defence answers the claim; a defendant's claim is your own claim.
How long do I have to serve it? Within 6 months after it is issued, according to the Ontario Courts page.