Negligence Primer: Standard of Care vs Duty of Care

By Mikkel Arnston

In this blog post, we go over two elements of negligence that can easily be confused: the duty of care and the standard of care.

In order to be liable for negligence, the person who purportedly committed the negligence (the “tortfeasor”):

  1. Must have owed a duty of care to the person claiming there was negligence (the “claimant”); and
  2. Must have breached the standard of care owed to the claimant.


These must be satisfied in succession. In other words, the question of the standard of care only becomes relevant if a duty of care is proven.

But what is the difference between these two things? The distinction is more easily drawn by example.

Consider a lawyer as a tortfeasor. A lawyer clearly owes a duty of care to their clients, but can a lawyer also owe a duty of care to persons who are not their clients?

The question of whether a duty of care is owed is established under the common law. This means that judges and the courts, by legal analysis, are tasked with determining the answer in any given situation. We rely on past court decisions to guide us. In the case of lawyers, the common law has established that lawyers do owe a duty of care to persons who are not their clients “when it is clear to both the lawyer and the claimant that the claimant was relying on the special legal skill and knowledge of the lawyer, and that the lawyer knew or ought to have known that the claimant was relying on his skill or knowledge”.

Once a duty of care is established, the standard of care becomes relevant. Continuing with the example of a lawyer, the standard of care that a professional like a lawyer must exercise can be informed by many sources. For instance, a lawyer would be expected to act responsibly and with reasonable skill and diligence, and this standard may be measured against the professional code of conduct for lawyers (set by the Law Society, the governing body for lawyers), and procedural rules and regulations like the Rules of Court.

The Courts would consider the situation and decide whether in that instance the standard of care was met or breached. This one question alone can be the focus of dispute in a negligence claim.

The duty of care and the standard of care are two distinct questions that must be assessed and analyzed. In order to be successful in a claim for negligence both must be proven as part of the larger legal test for negligence.


This post is meant to provide information only and is not intended to provide legal advice. Although every effort has been made to provide current and accurate information, changes to the law may cause the information in this post to be outdated.