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What to Do If a Former Employee Takes Trade Secrets in Ontario

An ex-employee walked off with client lists or confidential data? Here are the legal options an Ontario business has to respond — and what to do first.

Corporate6 min readTSLBy the Treadstone Law team · OntarioUpdated 2026-07
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Key takeaways
  • Canada does not have a single dedicated trade secrets statute the way some other jurisdictions do.
  • Do not let IT wipe the departed employee's devices or accounts before confirming what needs to be reviewed and preserved.
  • Which claims are realistically available depends heavily on the specific facts — what was signed, what role the employee held, and what evidence actually exists.

Discovering that a former employee left with your client list, pricing formulas, or product plans — and may already be using them at a competitor — is one of the more alarming moments an Ontario business owner can face. The good news is that Ontario law gives businesses real options in this situation. The bad news is that speed and documentation matter enormously, and many businesses lose ground in the first days simply by not knowing where to start.

This article walks through what counts as protectable confidential information, what to do immediately, and the legal claims and remedies available.

What Counts as a "Trade Secret" in Ontario

Canada does not have a single dedicated trade secrets statute the way some other jurisdictions do. Instead, protection comes through a combination of contract law, the equitable doctrine of breach of confidence, and — for more senior employees — fiduciary duty. Information is generally protectable where it is:

Client lists, pricing models, supplier relationships, proprietary processes, and unreleased product information can all qualify — but only if the business actually treated them as confidential in practice, not just in name.

Your Immediate Options When You Discover a Problem

  1. Preserve evidence before anything else. Do not let IT wipe the departed employee's devices or accounts before confirming what needs to be reviewed and preserved.
  2. Identify exactly what was taken. Vague suspicion is much harder to act on than a specific list of files, client records, or data that left with the person.
  3. Review what you signed with them. A confidentiality agreement, an employment contract with restrictive covenants, and any signed acknowledgment of company policies all shape your options.
  4. Send a clear written demand promptly, generally through a lawyer, requiring the return of materials and a stop to any further use or disclosure.
  5. Get legal advice on urgency. Some situations call for fast court action to prevent ongoing harm; others do not, and moving too aggressively without evidence can backfire.

The Legal Claims Available

ClaimWhat it targetsWho it can be brought against
Breach of contractViolation of a signed confidentiality or non-solicitation clauseThe former employee
Breach of confidenceMisuse of information treated as confidential, even without a written agreementThe former employee, and sometimes a third party who knowingly received it
Breach of fiduciary dutySenior employees or officers who owed a heightened duty of loyaltyThe former employee
Inducing breach of contractA new employer or competitor who knowingly encouraged the breachThe new employer or third party, in some circumstances

Which claims are realistically available depends heavily on the specific facts — what was signed, what role the employee held, and what evidence actually exists.

Court Remedies: Injunctions, Damages, and an Accounting of Profits

Where a court finds misuse of confidential information, available remedies can include:

Courts weigh these remedies against the specific facts; none is automatic, and urgent injunctive relief in particular requires meeting a real evidentiary bar, not just a strong suspicion.

Why Your Existing Agreements Matter So Much Right Now

A business's leverage in this situation is largely set well before the problem arises. A specific, well-drafted confidentiality agreement, clear policies on data access, and a documented offboarding process (revoked credentials, returned devices, a clear reminder of ongoing obligations) all make a claim far easier to prove — and can deter the conduct from happening in the first place. A business with none of these still has options through breach of confidence and fiduciary duty, but a much steeper evidentiary hill to climb.

Prevention: What This Means Going Forward

Frequently asked questions

How fast do I need to act if I discover a former employee took confidential data?

Quickly, particularly if the harm is ongoing — for example, if the person is actively using client information at a new employer. Delay can weaken a request for urgent court relief and give the impression the harm was not that serious, so get legal advice promptly rather than waiting to see how things unfold.

What if the former employee didn't sign a confidentiality agreement?

You still have options through the doctrine of breach of confidence and, if the person was senior enough, breach of fiduciary duty — but a written agreement makes the case considerably more straightforward to prove.

Can I go after the new employer, not just the former employee?

In some circumstances, yes — if the new employer knowingly induced the breach or is knowingly benefiting from misappropriated information, a separate claim may be available against them. This depends heavily on what can actually be proven about what they knew.

Is this a criminal matter, or only a civil one?

Most disputes of this kind proceed as civil claims between the business and the former employee (and potentially their new employer). Whether any separate law-enforcement dimension applies is a fact-specific question best raised directly with a lawyer.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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