How to Sue a Lawyer for Negligence in Ontario

In Ontario, you can sue a lawyer for professional negligence (also called legal malpractice). But these cases are complex, and there are strict rules about when and how you can bring a claim.

Let’s break down what you need to know.

Legal negligence occurs when a lawyer fails to provide the standard of care that a reasonably competent lawyer would provide in the same circumstances — and that failure causes you harm.

In simpler terms, your lawyer must act with reasonable skill, knowledge, and care. If they don’t, and you suffer a loss as a result, you may have grounds to sue.

Not every mistake is negligence. Lawyers are not required to be perfect, and they’re not guarantors of success. However, some common examples of legal negligence include:

Missing deadlines — Failing to file documents on time, causing your case to be dismissed or your rights to be lost.

Conflict of interest — Representing both sides of a dispute or having a personal interest that conflicts with your case, without your consent or waiver of the conflict. 

Giving bad legal advice — Providing advice that no competent lawyer would give in the circumstances, leading to a poor outcome.

Breach of fiduciary duty — Misusing trust funds, failing to communicate, or acting dishonestly.

Suing a lawyer for negligence is not easy. To succeed, you must prove three key things: 

This is usually straightforward. If you hired the lawyer or they agreed to represent you, they owed you a duty of care.

You must prove that the lawyer’s conduct fell below the standard of a reasonably competent lawyer. This often requires expert evidence from another lawyer who can testify about what a competent lawyer should have done.

This is the hardest part. You must prove that the lawyer’s mistake directly caused you to lose money, lose your case, or suffer another measurable harm.

This is called proving “causation,” and it often requires a “case within a case” analysis. In other words, you must show that if your lawyer had done their job properly, you would have likely won your original case or achieved a better outcome.

One of the most challenging aspects of suing a lawyer is that you essentially have to prove your original case all over again.

For example, if your lawyer missed a filing deadline and your personal injury lawsuit was dismissed, you must prove:

1. Your lawyer was negligent in missing the deadline; AND
2. If the deadline had been met, you would have likely won your personal injury case.

This means you need strong evidence not only about your lawyer’s mistake, but also about the merits of your underlying claim.

In Ontario, you generally have two years from the date you discovered (or should have discovered) the negligence to file a lawsuit against your lawyer.

However, limitation periods can be complicated, especially in legal malpractice cases. If you suspect your lawyer was negligent, it’s important to act quickly and consult with another lawyer as soon as possible.

If you win your case, you may be entitled to:

Compensatory damages — Money to cover the financial loss you suffered because of the lawyer’s negligence.

Costs — Reimbursement for some of your legal fees and court costs.

In rare cases, you may also be entitled to aggravated or punitive damages if the lawyer’s conduct was particularly egregious or dishonest.

At Pinto Shekib LLP, we have experience handling complex civil litigation matters, including professional negligence claims. If you believe your lawyer’s negligence caused you harm, we can help you understand your rights and options. 

If you’re considering a legal malpractice claim, contact us at 416.901.9984 or info@pintoshekib.ca for a confidential consultation