Rule 12.01 of the Small Claims Court Rules lets you amend a claim or defence by filing an amended, clearly marked version with the court. Whether leave of the court is required can depend on the stage your case has reached — the position is more straightforward before a defence is filed than after, and sources disagree on the exact mechanics once a defence is on file, so confirm the current requirement with a lawyer or the court before assuming you can amend freely.
- Rule 12.01 allows you to amend a claim or defence by filing a corrected version with the clerk, clearly marked "Amended".
- Amending to fix a typo, adjust a claimed amount within the court’s limit, or add detail is generally more straightforward earlier in the case.
- Whether leave of the court is required once a defence has already been filed is not entirely consistent across sources — do not assume you can amend freely at that stage without checking.
- Adding a new defendant after the fact carries a real risk if the limitation period for a claim against that person has already expired by the time you add them.
- An amended claim or defence generally needs to be properly served on the other parties, not just filed with the court.
- If the other side disputes your right to amend, the matter can end up before the court on a motion rather than being resolved by simply filing the amended document.
What Rule 12.01 Covers
Rule 12.01 of the Small Claims Court Rules sets out how a plaintiff’s claim, a defendant’s claim, or a defence can be amended after it has already been filed. In practice, this covers everything from fixing a typo or an incorrect address, to adjusting the amount claimed, to adding further detail about what happened — or, in some cases, adding or removing a party altogether.
An amendment is generally made by filing a corrected version of the document with the clerk, clearly marked "Amended," with new or changed text identified so the other side and the court can see exactly what changed from the original.
Amending Before a Defence Is Filed
Amending your claim before the defendant has filed a defence is generally the more straightforward scenario — at that stage, no one has yet formally responded to the specific wording you are changing, which reduces the chance that the amendment unfairly prejudices the other side.
Amending After a Defence Is Filed
Once a defence has already been filed, whether you need leave of the court to amend your claim is a point where available sources are not consistent. Some describe amendments as generally available without needing the court’s permission in most circumstances, while the Small Claims Court Rules also set out specific procedures — including motions to strike out or amend a pleading — that can come into play once the other side has responded. Do not assume you can amend freely at this stage without checking the current rule and, where the other side might object, getting advice on the right procedure.
Adding a New Defendant
Realizing partway through a case that someone else should have been named — a second contractor, a corporate entity instead of (or in addition to) an individual — is common. You can generally amend your claim to add that person or company as a defendant. The real risk is timing: if the limitation period for a claim against that specific defendant has already run out by the time you add them, they may be able to argue the claim against them is barred, even though your claim against the original defendant is still live.
A plaintiff sues an individual contractor for defective work, then later learns the work was actually performed through the contractor’s corporation. Amending to add the corporation as a defendant is generally possible, but if it happens close to or after the two-year limitation period has run from when the problem was discoverable, the timing of that amendment becomes critical to whether the claim against the corporation can proceed.
How to Actually File an Amendment
- Prepare a complete, corrected version of the claim or defence, marked "Amended"
- Clearly identify what has changed from the original version, as the rule requires
- File it with the Small Claims Court clerk
- Properly serve the amended document on every other party to the case
If there is any chance the other side will object to your amendment — particularly adding a new defendant — get advice before filing, rather than after a dispute over the amendment has already started eating into your time and the limitation period.
Getting It Right the First Time
Amendments exist precisely because claims are not always perfect on the first try. Still, the safest approach is to get the key details — the correct defendant, the right amount, the essential facts — right from the outset, since an amendment made late in the process, especially one adding a party, can run into limitation-period problems that a timely original claim would have avoided.
Need to amend a claim or add a defendant to an existing Small Claims Court matter in Toronto or anywhere in Ontario? Our lawyers offer a free 30-minute consultation. Call us at 416-274-2222 or contact us online.
Frequently Asked Questions
Yes. Rule 12.01 allows a plaintiff’s claim, a defendant’s claim, or a defence to be amended by filing a corrected, clearly marked "Amended" version with the court.
This depends on the stage of the case. Amending before a defence has been filed is generally the more straightforward scenario. Once a defence is on file, the position on whether leave of the court is required is not consistently described across sources, so confirm the current requirement before assuming either way.
Generally yes, by amending your claim, but this carries a real risk if the limitation period for a claim against that specific person or company has already expired by the time you add them — the new defendant can potentially argue the claim against them is time-barred.
If the amendment is contested, the matter may need to go before the court on a motion rather than being resolved simply by filing the amended document, so build in time for that possibility.
Yes. An amended claim or defence generally needs to be properly served on the other parties, not just filed with the court clerk.
In many cases yes, provided the amended amount still fits within the Small Claims Court’s monetary limit. Increasing beyond that limit raises separate issues about which court the claim belongs in.
Minor corrections are generally handled the same way as any other amendment under Rule 12.01 — file a corrected version marked "Amended" and serve it on the other side.