Can I sue? What to work out before you file in Ontario

Most people who ask a lawyer about suing have already decided they were wronged, and they are usually right. The harder question is whether a lawsuit is the way to fix it. Ontario gives you a deadline shorter than you expect, a costs rule that can turn a loss into a much bigger loss, and no way at all to collect from a defendant who has nothing.

A lawsuit needs a legal wrong, not just a bad outcome. Almost every civil claim in Ontario is one of four things:

• Breach of contract: Someone promised something and did not deliver. Verbal agreements are enforceable here; proving the terms is the hard part.
• Debt: An unpaid invoice, a loan, a personal guarantee. The cleanest claim, because the amount is fixed and the fight is usually about whether the work was done properly.
• Negligence: Someone owed you a duty of care, fell below the standard, and caused a measurable loss. A fall on someone's property, a botched renovation, bad professional advice.
• Misrepresentation: You were told something untrue, you relied on it, and you lost money. Common in business sales, used vehicles, and real estate.

Being treated unfairly is not by itself a cause of action, and neither is a broken promise that cost you nothing. If you cannot say in one sentence what the defendant did wrong and what it cost you in dollars, the claim is not ready.

Ontario's Limitations Act, 2002↗ sets a basic limitation period of two years. Section 4 bars a proceeding after the second anniversary of the day the claim was discovered. Section 5 defines discovery as the day you first knew four things: that the loss occurred, that an act or omission caused it, that the act or omission was the defendant's, and that a court proceeding would be an appropriate remedy. The clock actually starts on the earlier of that day and the day a reasonable person in your position ought to have known those same four things, so not looking into it buys you nothing.

Section 5(2) puts the burden where people do not expect it: you are presumed to have known all of that on the day the act or omission took place, and proving otherwise is on you. Discoverability saves real claims, particularly latent building defects and professional negligence that surfaces years later, but it is an argument you have to win. Section 15 caps everything at fifteen years from the act or omission, pausing only for minors, for claimants who lack capacity, and where the defendant deliberately concealed the wrong.

The shorter notice periods that catch people out

• Municipal roads and sidewalks: Section 44(10) of the Municipal Act, 2001↗ requires written notice of the claim and the injury, giving the date, time and location, served on the municipal clerk or sent by registered mail within 10 days of the occurrence. Section 44(12) lets a judge excuse a late or insufficient notice where there is a reasonable excuse and the municipality is not prejudiced, which converts part of your case into an argument about your own delay. Read section 44(9) as well: absent gross negligence, a municipality is not liable for a personal injury caused by snow or ice on a sidewalk.
• Snow and ice on private property: Section 6.1 of the Occupiers' Liability Act↗, in force since January 29, 2021, gives you 60 days from the injury to deliver written notice, with the date, time and location, to the occupier or to the contractor hired to clear the snow. Personal service or registered mail, and notice to one of them preserves the action against all of them.
• Claims against the provincial Crown: Section 18(1) of the Crown Liability and Proceedings Act, 2019↗ requires notice served on the Crown at least 60 days before you commence. Where the claim arises from the Crown's ownership or occupation of property, a fall on government premises being the everyday example, section 18(4) cuts that to 10 days after the event. Section 18(6) makes a proceeding brought without the notice a nullity, which is as final as it sounds.

Naming the wrong defendant is common, expensive, and unfixable once the limitation period has run. The business you dealt with might be a corporation, a numbered company, a franchisee, or a sole proprietor behind a trade name. The Ontario Business Registry↗ gives you the exact legal name and the address for service. Sue the entity that made the promise. If you believe a director or officer is personally on the hook, plead it deliberately: a corporation is a separate legal person, and the exceptions are narrower than people assume. We set them out in our post on personal liability for corporate owners.

A judgment is a piece of paper saying you are owed money. Enforcing it is a separate project with its own costs. Work out in advance what you would seize:

• Real property in Ontario, and whether any equity survives the mortgages.
• Employment income. Section 7 of the Wages Act exempts 80 per cent of wages from seizure or garnishment, measured after the deductions an employer is required by law to make, so a garnishment reaches 20 per cent of net pay unless a judge orders otherwise.
• Corporate assets. A numbered company with no property and an empty account is judgment proof, and beating it costs what beating a solvent defendant costs.
• Who ranks ahead of you. Registered security and certain CRA claims generally come first, and a bankruptcy stops your enforcement and leaves you sharing whatever is left with every other unsecured creditor.

This is the filter people skip, and skipping it wastes more money than anything else on this page. Sometimes the honest answer is that you have an excellent claim against a defendant nobody could collect from.

Civil cases turn on documents far more often than on who sounds convincing in the witness box. Before you meet a lawyer, put one file together: the contract or work order, every invoice and proof of payment, the full email and text thread, photographs and any estimate that prices the loss, your dated notes of calls and meetings, and anything in which the other side acknowledged the problem.

An admission in a text message is worth more than an hour of argument. Gaps are not fatal, since a lawsuit forces the other side to produce their documents too, but what you hold on day one drives both the settlement value and the cost of getting there. Businesses that run on handshakes learn this the hard way, which is why it leads our list of the legal mistakes that sink new Ontario businesses.

• Small Claims Court, up to $50,000: The limit rose from $35,000 on October 1, 2025. Filing a claim costs $108 for an infrequent claimant, and $308 more to fix a trial date. You can appear yourself or hire a licensed paralegal, and an appeal lies to the Divisional Court only where the judgment for money exceeds $5,000. Since July 1, 2024, section 23(1.1) of the Courts of Justice Act has barred starting an action in the Superior Court that belongs in Small Claims, except with leave. We walk through that court end to end in our guide to Small Claims Court in Ontario.
• Simplified procedure, $200,000 or less: Rule 76 is mandatory for money claims at or under $200,000. Discovery is limited, jury trials are unavailable, and rule 76.12.1 caps recoverable costs at $50,000 and disbursements at $25,000, excluding HST. Ontario summarizes the simplified procedure↗ in plain language.
• Ordinary procedure, above $200,000: Full documentary and oral discovery, a full trial, and no cap on what a costs award can reach.

Court fees are the small part of the bill. In the Superior Court it is $243 to issue a statement of claim, $194 to file a defence, $339 for a motion, and $859 for the first trial record, all listed on Ontario's civil court fees page↗. A single contested motion consumes more in lawyer time than every filing fee in the action.

A properly drafted demand letter is the cheapest useful step in this process, and a real share of disputes end there. It sets out the facts, the legal basis, the exact amount, the documents relied on, and a firm date to respond by. The letterhead does little of the work. What moves a recipient is a claim that is specific, documented, and plainly one step away from being filed. If you are working out the exact amount, our court interest calculator gives the prejudgment interest to add to it.

Two cautions. A demand letter does not pause the limitation clock, and negotiating politely for eighteen months while the two years quietly expires is a fact pattern we see every year. Never threaten criminal charges to collect a civil debt, either.

Section 131 of the Courts of Justice Act↗ puts costs in the court's discretion, and the Ontario default is that the loser pays a portion of the winner's legal fees on top of its own. Rule 57.01 lists what a judge weighs: the amount claimed against the amount recovered, complexity, the conduct of the parties, any offer to settle. Two scales matter.

• Partial indemnity: the ordinary award, calculated under Part I of Tariff A. It is a portion of what the winner actually paid their lawyer, never the whole of it.
• Substantial indemnity: defined in rule 1.03 of the Rules of Civil Procedure↗ as 1.5 times the partial indemnity amount, reserved for reprehensible conduct and for the consequences of a rejected offer to settle.

Rule 49.10 is the provision to understand before you turn an offer down. Where a plaintiff serves an offer at least seven days before the hearing begins, does not withdraw it, and then matches or beats it at judgment, the plaintiff gets partial indemnity costs to the date the offer was served and substantial indemnity costs from that date on. A defendant's offer bites differently. Under rule 49.10(2), a plaintiff who does no better than the offer still recovers partial indemnity costs up to the day it was served, then pays the defendant's partial indemnity costs for everything after. Turning down a reasonable offer on principle can cost more than the amount in dispute.

Small Claims Court is far gentler. Section 29 of the Courts of Justice Act caps a costs award there, disbursements aside, at 15 per cent of the amount claimed, so exposure on a $50,000 claim tops out at $7,500 unless the court penalizes unreasonable behaviour in the proceeding. Ontario publishes the current Small Claims Court filing fees↗.

A claim that settles on a demand letter can be done in a few months. Small Claims Court adds a settlement conference and then a wait for a trial date. A defended Superior Court action runs through pleadings, documentary discovery, examinations for discovery, mediation, a pre-trial conference, and only then a trial. Rule 48.14 shows the pace the system assumes: the registrar dismisses an action for delay if it has not been set down for trial by its fifth anniversary. Plan on well over a year for a defended action.

Not all of that year is spent waiting. In Toronto, Ottawa, and the County of Essex, rule 24.1.04 makes mediation mandatory, and that session is where a great many of these cases end. Procedure is in flux as well. The Superior Court's Civil Rules Review↗ released its final report on December 15, 2025, and what it proposes has yet to come into force. The deadlines above are unaffected either way.

1. 01What exactly did they do wrong, and what did it cost me in dollars?
2. 02When did I discover the loss, and is there a notice period measured in days rather than years?
3. 03Who is the correct defendant, by exact registered name?
4. 04If I won, what specifically would I collect from, and how?
5. 05What can I prove on paper today, without anyone's cooperation?
6. 06Is the amount worth the fee, the wait, and the risk of paying the other side's costs if I lose?

Where the answers are strong, file early rather than at the edge of the deadline. A limitation argument is one you can lose without ever reaching the merits, and no judge gets to hear how good your case was. Where the answers are weak, a well-aimed demand letter often gets you more of what you wanted, sooner and cheaper.

A lawyer earns the fee at three points: spotting the notice period before it expires, naming the right defendant while there is still time to amend, and saying plainly when a claim is not worth what winning will cost. If you are weighing one, Telesh Law Firm Professional Corp handles civil litigation across the GTA and can tell you which of these six questions decides your file.

• Ontario courts
• Deadlines
• Cost & fees

This article is general information, not legal advice, and does not create a solicitor-client relationship. It is current as at its publication date and is not revised as the law changes. For advice on your specific situation, book a consultation or call 416-639-0887.

Written by

Caleesis Telesh

Founder & Principal Lawyer

LL.B. · B.A., York University · Member, Law Society of Ontario

Full profile→LinkedIn↗