Yes, and it is the most common ground. The testator must understand the nature of making a will, the extent of their property, and who might expect to benefit.
The Canadian position
Capacity is assessed at the time of signing. Suspicious circumstances can shift the burden onto the person propounding the will.
The Islamic position
Classical fiqh likewise requires soundness of mind for a valid wasiyyah, and treats deathbed dispositions under separate rules.
No school requires a lawyer, a notary or any set form: a wasiyyah is made by words, and the four are agreed that a written one operates exactly as a spoken one does. Where they part company is on who may make one — the Hanafi and Shafi’i schools require adulthood, the Maliki and Hanbali schools only discernment — and on what a document found in the deceased’s handwriting proves. Sound mind, freedom and a free will are conditions in all four, and all four let a testator revoke at any time.
All four Sunni schools researched and sourced. Reviewed 2026-09-01. Full positions, evidence and sources — Making a wasiyyah — form, capacity and revocation.
Related madhhab issue: A gift made in the final illness — gift or bequest?.
Making an Islamic will in Canada — province by province, and what makes one valid where you live →
What to do about it
- Make the will while clearly well, not in a crisis.
- Have the lawyer record capacity observations.
- Consider a capacity assessment if there is any history of cognitive difficulty.
This is legal information only. For advice on your own circumstances, speak to a lawyer.
Citations & sources
Every factual claim on this page traces to a source below. Details change — check the original source before relying on any figure, fee or legal position. Anything under “further reading” is related material, not a source for what is stated here.
- Grewal v. Litt, 2019 BCSC 1154 — CanLII
- Wills, Estates and Succession Act, SBC 2009, c 13 — BC Laws
- Canadian Legal Information Institute — CanLII
- Substitute Decisions Act, 1992 — Government of Ontario
- Suspicious circumstances doctrine will challenge ontario — Treadstone Law
- Common mistakes making a will ontario — Treadstone Law
- Capacity to instruct a lawyer ontario — Treadstone Law
- Testator capacity decline updating will ontario — Treadstone Law
- Wills & estates practice — Treadstone Law