Predatory Marriage in Ontario: How It Can Be Challenged to Protect an Estate

Predatory marriage is the term used when someone marries a vulnerable, often elderly or cognitively impaired person, largely to gain access to their estate. It's one of the more painful situations families bring to a wills and estates lawyer, because by the time it's discovered, the marriage has usually already happened.

The good news is that a marriage is not automatically unchallengeable just because it took place. There are specific, well-established legal routes available — during the person's life or after their death — to question whether the marriage, and anything signed around it, should stand.

What Makes a Marriage "Predatory"

There's no single legal checklist, but the pattern families describe tends to share a few features:

• A large or sudden age gap, or a relationship that developed unusually quickly
• The vulnerable person showing signs of declining cognition, illness, or isolation from family
• The new spouse taking over finances, limiting family contact, or discouraging outside advice
• A marriage kept secret from family until after the fact
• New estate planning documents — a will, a power of attorney, or beneficiary changes — signed shortly before or after the marriage, generally in the new spouse's favour

None of these facts alone proves wrongdoing. Together, they're often what prompts a family to seek legal advice about whether the marriage or the documents around it can be challenged.

Why Marriage Timing Used to Matter So Much

For marriages that took place before January 1, 2022, marriage automatically revoked an existing will under Ontario law — meaning a predatory marriage could silently wipe out a carefully planned will and send the estate into intestacy, where the new spouse could stand to inherit a significant share.

That automatic revocation rule was repealed effective January 1, 2022, and the repeal is not retroactive. In practical terms:

• Marriages on or after January 1, 2022 no longer automatically revoke an earlier will.
• Marriages before that date could still have revoked a will made before the marriage, under the old rule.

This change reduces one historical incentive behind predatory marriage, but it does not eliminate the risk. A vulnerable person can still be persuaded to sign a brand-new will favouring a new spouse, or to leave no valid will at all, in which case Ontario's intestacy rules would give a legally married spouse an automatic inheritance that a common-law partner would never receive.

The Legal Routes to Challenge It

Challenging capacity to marry

Marriage has its own legal requirements, separate from the requirements for making a valid will. Courts have generally recognized that the capacity needed to marry is a distinct — and often less demanding — legal standard than the capacity needed to make a valid will, which is part of what makes predatory marriage such a difficult area: a person might be found capable of marrying while a will signed around the same time is still open to challenge on capacity or undue influence grounds.

Challenging the will or other documents signed around the marriage

If a new will, power of attorney, or beneficiary designation was signed close to the marriage, it can potentially be challenged separately on familiar grounds:

• Lack of testamentary capacity at the time the document was signed
• Undue influence by the new spouse or someone connected to them
• Lack of knowledge and approval of what the document actually said

Relying on intestacy and dependant support protections

If the vulnerable person dies without a valid will, only a legally married spouse — not a common-law partner — has an automatic right to inherit under Ontario's intestacy rules. Family members who are cut out entirely may still be able to bring a dependant support claim if they qualify as a dependant under the applicable rules, though this is a distinct legal avenue with its own requirements and timeline.

Acting While the Person Is Still Alive

Families sometimes discover a predatory relationship while their loved one is still living. In that situation, legal options can include:

• Raising capacity concerns with the person's doctor or seeking a formal capacity assessment
• Reviewing whether an existing power of attorney is being misused, since an attorney for property has a fiduciary duty to act in the vulnerable person's interest, not their own
• Applying to the court, in serious cases, regarding guardianship if the person is found to lack capacity to manage their own affairs and no valid power of attorney is in place

Acting early — before assets are moved or new documents are signed — is generally far more effective than trying to unwind everything after death.

Frequently asked questions