Should You Write a Letter Explaining Why You Disinherited Someone in Ontario?

If you're planning to leave someone out of your will — an adult child, a sibling, someone who would ordinarily expect to inherit — it's natural to want to explain why. A separate letter of wishes is a common way people try to do this: a document, kept alongside the will, that lays out the reasoning behind a difficult decision.

The instinct makes sense. Whether it actually helps if the will is later challenged is a more nuanced question, and the honest answer is: it depends on how it's written, what it says, and the specific circumstances — not something a template can guarantee.

What a Letter of Wishes Actually Is

A letter of wishes is generally not a legally binding document in the way a properly signed and witnessed will is. It doesn't distribute property, and it doesn't override what the will itself says. Its role is closer to context: a way of recording the testator's own explanation, in their own words, for a decision the will carries out.

Because it sits outside the formal will, it doesn't need to meet the same signing and witnessing formalities — but that same informality is part of what makes its legal weight uncertain if a dispute arises later.

How a Letter of Wishes Can Help

There are real reasons estate lawyers sometimes recommend one:

• It can provide contemporaneous evidence of the testator's state of mind and reasoning, written closer in time to when the will was made — which can be more persuasive than family members reconstructing the testator's thinking after death, from memory or secondhand accounts.
• It can address, directly and calmly, why a decision was made — estrangement, prior financial support already provided, a genuine difference in circumstances between beneficiaries — in the testator's own voice rather than left to speculation.
• It can reduce the sense of shock or mystery that sometimes fuels disputes in the first place. Family members who understand a decision, even if they disagree with it, are sometimes less likely to escalate into formal litigation than those left with no explanation at all.

How It Can Also Backfire

The same letter can create problems it was meant to avoid:

• It can hand a disappointed beneficiary a roadmap. A letter that reveals uncertainty, ambivalence, or reasoning based on incomplete or mistaken information can actually strengthen a challenge rather than weaken it — particularly on grounds like the testator's capacity or true intentions.
• It can introduce inconsistency. If the letter's tone or reasoning doesn't align cleanly with the will itself, or with other evidence about the testator's relationships, that gap can become a focal point in litigation rather than a resolution of it.
• It carries less formal weight than the will, which means it can be scrutinized, minimized, or contested on the basis that it doesn't reliably reflect the testator's considered, final intentions — especially if it was written well before death, or under emotional circumstances.
• It cannot cure an otherwise problematic will. A letter of wishes doesn't fix genuine legal problems with the will itself, such as questions about capacity or undue influence — if those issues exist, an explanatory letter doesn't resolve them and may draw more attention to them.

Weighing the Two Sides

Practical Guidance If You're Considering One

1. Don't treat it as a substitute for a properly drafted will. The legal effect comes from the will; the letter only supplements it.
2. Keep the tone factual, not emotional. A letter written in anger tends to raise more questions about state of mind than it answers.
3. Have it reviewed alongside your will, not drafted separately and filed away without a lawyer ever seeing both documents together.
4. Update it if your reasoning changes — an outdated letter that no longer reflects your actual thinking can be as much of a liability as having none at all.
5. Understand it won't guarantee anything. A letter of wishes can be persuasive context in a dispute; it is not, on its own, a legal shield against a will challenge or a dependant's support claim.

Frequently asked questions