The basic rule: 2 years
Ontario's Limitations Act, 2002 sets a general 2-year limitation period for civil claims, including personal injury. The clock runs from the date the claim was discovered — which is usually the date of the incident, but not always (see discoverability below). If you don't start a lawsuit within that window, you generally lose the right to sue, no matter how strong the case was.
Discoverability: the clock doesn't always start at the crash
The law says the clock starts when you knew — or a reasonable person ought to have known — three things: that you were injured, that someone's act or omission caused it, and that a court proceeding was an appropriate remedy. Example: symptoms from a "minor" collision that turn out, months later, to be a serious spinal injury. The discovery date can be later than the incident date — but proving that is a lawyer's job, not a DIY argument.
The deadlines shorter than 2 years
Some defendants get special protection:
- Municipalities: slip-and-fall or snow/ice claims against a city or town can require written notice within 10 days of the incident. Miss it and the claim can die in week two.
- Provincial Crown: claims against Ontario government bodies have their own notice requirements and timelines.
- Insurance contracts: your own accident-benefits claim has contractual notice deadlines that are much shorter than 2 years.
This is exactly why the quiz asks about timing first — a "strong" case on liability and damages can still be worthless if a deadline has passed.
Is timing working against you?
The free 10-question quiz scores your timing risk alongside liability and damages — and tells you what to do in the next 7 days.
Take the free quizExceptions exist — don't rely on them
The limitation clock is paused while a potential claimant is a minor (under 18) or incapable, with the clock generally starting when a litigation guardian is appointed or capacity returns. There are other narrow exceptions. Treat every exception as something a lawyer argues for you — never as a reason to wait.
What to do right now
- Write down the exact date of the incident and the date you first connected it to your injury.
- Check whether a municipality or government body could be involved — if so, assume the notice deadline is days, not years.
- Do not wait for treatment to finish before getting advice. The deadline doesn't care about your physio schedule.
- Get a free case review — a lawyer can calculate your actual deadline in one conversation.
Related reading: how car accident case values work in Ontario.