Can Handwritten Changes to a Will Be Valid in Ontario?

Can You Change a Will by Writing on It After Signing?

No — in Ontario, writing on a signed typed will does not legally change it. A recent Superior Court decision, Boyle v. Boyle, 2026 ONSC 4919 (CanLII) (read the decision), confirmed that handwritten notations, strikethroughs, and dated entries added to a typed will after it was signed are invalid unless they meet strict legal formalities — and in this case, they did not.

For families sorting out an estate, this distinction matters enormously. If a testator believed their handwritten changes would redirect assets, those intentions may simply not be honoured.

What Are the Rules for Altering a Will in Ontario?

Ontario’s Succession Law Reform Act sets out clear requirements for altering a typed (non-holograph) will. Any change made after the will is signed must itself be signed by the testator and witnessed by two subscribing witnesses — the same formalities required when the will was first executed.

In this case, the testator had initialled some of the handwritten notations in the margin, but there were no subscribing witnesses. That gap was fatal. Initials alone, without witnesses, do not satisfy the statutory requirements, and the alterations were held to have no legal force or effect.

Can a Court Validate Informal Changes to a Will?

Sometimes — but not automatically. Ontario courts have a curative power under section 21.1 of the Succession Law Reform Act to validate documents that fall short of formal requirements, if the court is satisfied the writing represents a deliberate, fixed, and final expression of the person’s testamentary intentions.

In this case, the court accepted that the handwriting was genuinely the testator’s. However, authenticity alone is not enough. The court found the notations did not reflect a sufficiently settled and final intention about how the estate should be distributed. As a result, the court declined to exercise its discretion to validate the changes.

Does Writing on a Will Cancel the Original Clauses?

Not necessarily. Even where alterations are invalid, the question becomes whether the original typed words can still be read. Under section 18(1) of the Succession Law Reform Act, an alteration can only invalidate existing words if those words are no longer apparent — meaning they can no longer be read.

Here, the strikethroughs and handwritten additions did not physically obscure the typed residue clause. The original words remained clearly legible. The court confirmed the residue clause as originally written, meaning the estate was distributed under the will rather than falling into a partial intestacy.

What Is a Partial Intestacy and Why Does It Matter?

A partial intestacy occurs when part of an estate is not covered by a valid will — for example, if a residue clause is struck out and the alteration is invalid but the original clause is also unenforceable. In that scenario, the uncovered portion passes under Ontario’s intestacy rules rather than the testator’s wishes.

The court’s finding that the original residue clause remained valid prevented a partial intestacy here. That outcome avoided the uncertainty and potential family conflict that intestacy rules can produce, particularly in blended or complex family situations.

How Should You Change a Will in Ontario?

The safest approach is to have a lawyer prepare a formal codicil or an entirely new will. A codicil is a supplementary document that amends a specific part of an existing will while leaving the rest intact. Like a will, it must be signed and witnessed properly to be legally effective.

Writing directly on a will — even with good intentions and genuine initials — creates serious risk. If those changes are later challenged or found invalid, the original terms govern, which may not reflect what the testator ultimately wanted. Our Ontario wills and estates lawyers regularly help clients update their estate plans in a way that holds up legally.

Questions and Records to Discuss with a Lawyer

• Were any changes made to a will after it was originally signed, and if so, how were those changes documented?
• Are there handwritten notes, crossed-out sections, or marginal annotations on the original will?
• Did the person who made the will sign and date any changes, and were witnesses present at that time?
• Is there any other document — a letter, a note, a separate page — that might reflect the testator’s intentions about their estate?
• Has the original will been located and reviewed by a lawyer to confirm which clauses remain enforceable?

If you are dealing with a will that has been marked up or altered, or if you are uncertain whether a loved one’s final wishes will be carried out as intended, the team at UL Lawyers is available to discuss your circumstances at ullaw.ca/connect. We assist clients in Burlington, Hamilton, and across Ontario with estate matters of all kinds — including those involving our probate lawyers and executor liability questions at /practice/wills-estates/executor-liability.

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This article is automated commentary on a public court decision and is for general information only — not legal advice. Decisions rely on facts unique to each case. If you are affected by a similar issue, contact a lawyer for advice specific to your situation.