Professionals are paid for their judgment, and most clients hand over decisions they could never check themselves. So when a tax filing triggers a reassessment you were told would never come, or a home inspection misses a failing foundation, or a real estate deal closes with a problem no one flagged, the feeling of betrayal can be strong. Whether you have a legal claim is a different question.
A negligence claim against a professional asks whether the work fell below what a reasonable member of that profession would have done, and whether that failure caused you a real financial loss. Many unhappy outcomes do not meet that test. Some do, and in those cases the time to act may be shorter than you think.
This post is general information and not legal advice. If you are thinking about a claim against any professional, including a lawyer, get independent advice about your own facts and your deadline as soon as possible.
What You Have to Prove
Any negligence claim has the same basic elements, and the person suing has the burden of proving each one on a balance of probabilities.
A duty of care. This is seldom the hard part where you were the client. It is harder where you were not. A buyer who relied on a report prepared for the seller, or an investor who read an auditor’s opinion, might or might not be owed a duty, depending on what the professional undertook and the purpose of the work.
A breach of the standard of care. Professionals are measured against a reasonably competent member of the same profession in similar circumstances. Someone holding themselves out with more specialized training may be held to a higher standard. Professionals are not expected to be perfect, and an honest judgment call that later proves wrong may not be negligent if it was within the range of reasonable practice.
Causation. You generally have to show that but for the breach, the loss would not have happened. This is where many claims weaken. If your accountant missed a filing but you would have owed the tax anyway, your real loss might be limited to penalties and interest.
Damages. You need a measurable loss. A claim is only worth what can be proved. In a lawsuit against a former lawyer over a case that was lost, a court may effectively have to ask what would have happened in the original dispute, and what the claim was worth, including whether it could have been collected. These calculations are complicated.
Contract, Too
Your relationship with a professional is usually a contract as well. Many claims allege both breach of contract and negligence. The retainer letter or engagement letter is therefore a vital document, because it defines the scope of the work.
Scope is a common defence. An accountant might say the engagement was limited to preparing a return from the information provided, not to auditing it. A home inspector’s agreement may limit the inspection to visible components, and may also limit liability to the fee paid. Clauses of that kind are not always enforceable, particularly where consumers are involved, but they can have a big effect. Read what you signed before you assume anything.
Why Expert Evidence Usually Matters
The most distinctive feature of these lawsuits is the need for an expert. A judge is not assumed to know how a structural engineer should have sized a beam or what a reasonable accountant would have done about a particular filing. The Court of Appeal for Ontario addressed this in Krawchuk v. Scherbak, 2011 ONCA 352, a case involving real estate agents: as a general rule, a trial court should not determine the standard of care in a professional negligence case without expert evidence. Two exceptions are recognized. One covers non-technical matters within an ordinary person’s knowledge. The other covers conduct so egregious that it obviously fell short.
A missed deadline, a forgotten closing date, or a failure to do something the client expressly instructed may fall within these exceptions, depending on the facts. Claims that turn on professional judgment usually will not.
For you, this means:
- Budget for an independent expert from the same field, preferably early. An opinion can tell you if the case is worth pursuing at all, before you spend heavily on court steps.
- Expect the defence to have its own expert, and possibly their professional liability insurer funding it.
- Know the rules for experts at trial. Rule 53.03 requires reports to be served within set timelines before the pre-trial conference, and the expert must acknowledge a duty to the court rather than to the party paying them.
Time Limits: The Part People Get Wrong
Ontario’s basic limitation period is two years from the day a claim was discovered. Under section 5 of the Limitations Act, 2002, this is the earlier of the day you actually knew the key facts and the day a reasonable person in your position ought to have known them. Those facts are that a loss occurred, that it was caused by an act or omission of the person you intend to sue, and that a legal proceeding would be an appropriate way to fix it. You are presumed to have known these on the day of the act or omission, unless you can show otherwise.
Professional negligence claims often raise tricky questions about this date.
You do not need certainty. The Supreme Court of Canada held in Grant Thornton LLP v. New Brunswick, 2021 SCC 31, a case about auditors, that a claim is discovered when the plaintiff has knowledge, actual or constructive, of material facts on which a plausible inference of liability can be drawn. That case arose under New Brunswick’s statute, but Ontario courts have also looked to it. In other words, you may not be able to wait for an expert’s report to tell you what you already suspected.
Ongoing help can matter, but do not rely on it. If a professional is actively trying to fix the problem, and you reasonably rely on that, this might affect when a lawsuit becomes “appropriate.” These are fact-driven arguments and should be a back-up, not a plan.
There is a final cut-off. The ultimate limitation period is generally 15 years from the act or omission, whatever you knew. Limited exceptions apply for minors and people incapable of commencing a proceeding, and for wilful concealment.
If you think something went wrong, write down when and how you first suspected it. Then get advice right away, since that date may determine your rights. Contracts sometimes attempt to shorten these periods, and whether that works depends on the type of agreement and the Act’s rules.
A Regulatory Complaint Is Not a Lawsuit
Many professionals in Ontario answer to a regulator: the Law Society of Ontario for lawyers and paralegals, Chartered Professional Accountants of Ontario for CPAs, Professional Engineers Ontario for engineers, the Real Estate Council of Ontario for real estate agents and brokers, the College of Physicians and Surgeons of Ontario for doctors, and so on.
These bodies focus on professional conduct and public protection. They can investigate, discipline or impose requirements, but generally do not compensate you for what you lost. A complaint does not stop the limitation clock on a civil claim. It might provide useful information, although the rules on using complaint materials in court can be restrictive, particularly in the health field.
There can be reasons to do both, or only one. Think about your goals. Do you want money? Do you want the conduct to be looked at? Do you want a fee dispute resolved? A bill from a lawyer can usually be reviewed through a process called assessment, separate from a negligence claim. Accounting and other professional bodies have their own arrangements for fee disputes, and the deadlines can be short.
Who Actually Pays
Many regulated professionals carry insurance, and for some it is mandatory. Lawyers in private practice in Ontario, for instance, generally carry coverage through LAWPRO. Insurance can make a judgment collectible, and an insurer may take over the defence and settlement decisions.
Sometimes, though, coverage can be limited, or a policy may exclude certain conduct. Some people practising without proper credentials have no insurance at all. Under Rule 30, an insurance policy that may respond to a judgment must be disclosed in the lawsuit. A claim may also name the firm as well as the individual, depending on how the work was structured and contracts were signed. A company that employs the professional might be vicariously liable too.
You should also expect to hear about your own conduct. If you ignored a warning letter, or did not give the professional the full picture, the defence could argue contributory negligence, which may reduce any award. Ontario’s Negligence Act allows a court to divide fault between parties.
Where the Claim Goes
Claims up to $50,000 belong in Small Claims Court, where the procedure is simpler and costs are limited. Some claims against, for example, a tax preparer, a home inspector or a bookkeeper may fit there, though the cost of an expert has to be weighed against the amount at stake. Claims above that usually proceed in the Superior Court of Justice, with the Brampton courthouse being the natural location for many Peel disputes, and those up to $200,000 will typically go under the simplified procedure, with its three-hour discovery limit and capped costs. Larger or more complex cases may use the ordinary procedure.
First Steps If You Suspect a Problem
- Secure your file. Ask for a copy of your file in writing, and keep copies of what you already have. You are generally entitled to much of your own material, though the rules vary by profession.
- Reduce your losses. Courts expect you to take reasonable steps to limit damage. Hire a new professional to fix the problem, and keep invoices showing the extra cost.
- Do not sign a release or accept a refund without understanding what you could be giving up.
- Stay measured. Avoid online reviews that make allegations you cannot prove, since these could create a separate problem for you.
- Get a limitation opinion early. Keep the date of your first concern at the front of your file.
Bringing a claim against someone whose expertise you relied on can feel daunting, but an early, candid assessment can tell you whether the numbers and the evidence justify going ahead. The firm’s contractual litigation page describes related disputes over services, and you can reach Sawan Law House LLP to discuss your documents and timeline. Bring the engagement letter, the work product and the date you first suspected a problem.