The deadline to start a lawsuit is called a limitation period. If you miss it, the court can dismiss your claim without hearing whether you were right. The other side does not have to prove you were wrong. They only have to show you were late.
This page is information, not legal advice. Limitation rules depend on your province, the type of claim, and the facts. Quebec uses its own civil law system and its own terms. A lawyer can tell you the deadline that applies to your case.
The basic rule in most provinces
Ontario, British Columbia, and Alberta each set a basic limitation period of two years. The clock does not start on the day you first feel upset about a problem. It starts on the day you “discover” the claim, which the statutes define in their own words.
In Ontario, a claim is discovered on the day you knew four things. You knew you had suffered an injury, loss, or damage. You knew it was caused by an act or omission. You knew the act or omission was by the person you want to sue. You knew a lawsuit was an appropriate way to respond. The law presumes you knew all of this on the day the act happened, unless you can show otherwise.
British Columbia and Alberta use similar ideas. Both ask when you knew, or reasonably should have known, that you had a claim. The details differ, so read the statute for your province or ask a lawyer.
The ultimate limit
Most provinces also set a second, outer deadline. It is called an ultimate limitation period. It runs from the day of the act or omission, whether or not you knew about the claim.
Ontario and British Columbia set the ultimate limit at 15 years. Alberta sets it at 10 years. A person who finds out about a problem late can still lose the right to sue if the outer limit has passed. Some situations pause or extend the ultimate limit, such as a claim by a person who was a minor or who lacked capacity. The rules are narrow.
Quebec
Quebec does not use the term “limitation period” in the same way. Its Civil Code sets a general prescription period of three years. Other periods apply to specific claims. Talk to a Quebec lawyer for the rule that fits your situation.
Examples of when the clock starts
A car accident is the simple case. You know about the injury, the cause, and the other driver on the day of the crash. The two-year clock in Ontario, British Columbia, or Alberta starts then. Some injuries show their full effect later, and that can raise a real question about discovery. Do not count on that argument. Treat the accident date as the safe starting point.
A broken contract is different. If a contractor stops work on May 1 and walks away, the claim for breach arises on that date. If a supplier delivers faulty goods and the defect shows up months later, the discovery date may be later than the delivery date.
A debt follows its own path. A loan with a repayment date usually gives rise to a claim when the borrower misses the payment. The two years run from the missed date, not the date of the loan.
What counts as starting a lawsuit
You meet the deadline by starting the case in court. In most provinces, that means filing the claim with the court within the limitation period. Writing a demand letter does not stop the clock. Talking with the other side does not stop it either.
Filing is only the first step. After you file, you must still serve the defendant within the time the court rules allow. Our guide to the stages of a civil lawsuit in Canada shows where filing and service fit in the full process.
Things that can change the deadline
Several situations can pause, extend, or shorten the time.
Age and capacity. The clock may not run while a person is a minor or lacks the capacity to bring a claim. The rules vary by province.
Written agreements. Parties can sometimes agree in writing to extend a limitation period or to suspend it while they try to settle. The agreement must meet the rules in your province. An informal promise to “work something out” does not count.
Acknowledgment of a debt. In some provinces, a written acknowledgment or a payment toward a debt can restart or affect the clock. The rules differ.
Claims against governments. Lawsuits against a municipality, a province, or the federal government can come with special notice requirements. Some notice periods are much shorter than two years. You may have to send written notice before you can sue at all.
Special statutes. Certain claims, such as those involving some types of injury, insurance, or employment, have their own deadlines. A few claims have no limitation period at all in some provinces. Do not assume the two-year rule applies.
Small claims. Small claims courts follow the same limitation rules as the higher courts in most provinces. The lower dollar amount does not give extra time.
Why the other side can raise it late
Limitation is a defence. The defendant must raise it in their response to the claim. If they do not, the court may not apply it. A defendant who ignores the claim loses the chance to raise the point. Our article on what happens if you ignore a statement of claim in Canada explains the risks of default.
A plaintiff should not count on the other side missing the defence. File on time.
Steps to take if you think you have a claim
Write down the key dates. Note the date of the event, the date you learned of the harm, and the date you learned who was responsible. Keep emails, receipts, photos, and contracts.
Count forward from the earliest date. Mark two years on a calendar. Treat that date as the deadline until a lawyer tells you otherwise.
Check for notice rules. If the other party is a government body, ask about notice requirements right away.
Talk to a lawyer early. A lawyer can name the correct limitation period, spot special rules, and file the claim in time. If cost is a concern, ask your provincial law society about its lawyer referral service. Legal aid, community legal clinics, and court self-help centres may also help, depending on where you live and your income.
Do not wait for settlement talks to finish. Talks can drag on past the deadline. Unless you have a signed agreement that pauses the clock, file the claim.
What to do if you think you missed the deadline
Do not assume the claim is dead. The date you discovered the claim may be later than you think. A special rule may apply. The other side may have signed an agreement or acknowledged a debt in writing. A lawyer can review the facts and tell you whether a claim is still open.
If the deadline has clearly passed, a court can still hear the case if the defendant fails to raise the defence. That is a weak path and not a plan.