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№ 22 Wills & Estates

Challenging a Will for Lack of Capacity in British Columbia

Think a relative had dementia when signing a will? Learn how capacity challenges work in British Columbia, what evidence matters and what to do next.

Wills & Estates5 min readTSLBy the Treadstone Law Team · British ColumbiaUpdated November 6, 2026
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Key takeaways
  • A person must be 16 or older and mentally capable of making a will, and a will made without mental capacity can be challenged as invalid.
  • A notice of dispute can pause probate, but it lapses after one year unless the court renews it.
  • Capacity is often argued alongside undue influence and signing formalities, so look at all three.

If a parent or relative had dementia or another serious illness around the time they signed a will, it is natural to wonder whether they understood what they were doing. The question can feel urgent, especially when the will changes what you expected.

This article explains in plain terms how British Columbia law treats capacity, what kinds of evidence tend to matter, and how you can slow down probate while a concern is looked into. It is general information, not advice on your situation.

This article covers the law of British Columbia.

What the law requires of a will-maker

Under section 36(1) of the Wills, Estates and Succession Act (WESA), a person who is 16 years of age or older and mentally capable of doing so may make a will. A will made without mental capacity can be challenged as invalid.

How a court applies the capacity requirement to a particular person, including where a diagnosis such as dementia is involved, depends on the facts, so it is worth confirming with a lawyer. Medical records and the accounts of people who were present can help show the person's condition, but how that evidence is weighed is something a lawyer can help you assess.

What evidence tends to matter

Evidence is central to any dispute about capacity, and what counts depends on the facts. If you are thinking about a challenge, start by working out what records and witnesses might exist.

Other grounds that often come up with capacity

Capacity is rarely the only issue. A will must be in writing and signed at its end by the will-maker, or the signature acknowledged, in front of two or more witnesses present at the same time, and at least two of them must then sign in the will-maker's presence. A document that misses these steps can sometimes still be upheld, because the court may order that a record is fully effective as the will even though it does not comply with the Act.

Undue influence is another ground. If a person claiming undue influence shows that someone was in a position where the potential for dependence or domination of the will-maker was present, the party defending the will or gift then has the onus of proving that no undue influence was exercised. This can matter where a vulnerable person relied on a caregiver or family member.

Pausing probate while you look into it

A person who must be given notice of the probate application, or who claims an interest under a prior or later will, may file a notice of dispute. It must be filed before the earlier of the issue of an authorization or of the estate grant. It uses Form P29 and must give an address for service, and you cannot file more than one for the same estate.

While a notice of dispute is in effect, the registrar must not issue an estate grant for that estate. It stops being in effect after one year, at the end of any renewal period, if you withdraw it, if the will is proved in solemn form, or if the court orders it removed. The court may renew it for a period it considers appropriate, but a late renewal application requires you to show good reasons it could not be brought earlier, substantial prejudice to you and no substantial prejudice to other interested persons.

Any person interested in the estate may apply to remove a notice of dispute, and the court may order removal if the filing is not in the best interests of the estate. Proof in solemn form means the court pronounces for the force and validity of the will after a trial or hearing.

What to do next

Frequently asked questions

Does a dementia diagnosis automatically make a will invalid?

A will made without mental capacity can be challenged as invalid, and the question is whether the person was mentally capable when making the will. How a diagnosis such as dementia affects that question depends on your situation, so it is worth confirming with a lawyer. A lawyer can explain how the medical evidence is weighed.

Can I stop probate while I decide whether to challenge the will?

You may be able to file a notice of dispute in Form P29 before the grant is issued, which stops the registrar from issuing a grant while it is in effect. It lapses after one year unless the court renews it.

Who pays the legal costs if a challenge fails?

The general rule is that costs are awarded to the successful party unless the court orders otherwise. The court may also make a costs order against a party who does something improperly or unnecessarily. How this plays out in estate cases depends on the facts.

What if I am a spouse or child and the will is valid?

A spouse or child may be able to bring a wills variation claim if the will does not make adequate provision for their proper maintenance and support. The proceeding must be started within 180 days from the date the grant is issued in British Columbia.

Sources

Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. British Columbia 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 lawyer who practises in British Columbia. Reach us at 1-844-900-1070 or send our Team a message.

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