Multiple Wills in Ontario: The Risk of Inconsistent or Conflicting Provisions

Using a primary will and a secondary will is a well-established Ontario estate-planning technique, particularly for business owners with private company shares. It's a legitimate way to reduce the portion of an estate exposed to probate. But multiple wills only work as intended when the two documents are drafted so they clearly divide the estate between them — and the risk of getting that division wrong is one of the more consequential drafting mistakes in this area of practice.

If you have, or are considering, more than one will, understanding where these plans typically go wrong is worth the read.

Why Ontario Estate Plans Use Multiple Wills

The idea is straightforward: a primary will covers assets that generally require a Certificate of Appointment of Estate Trustee to be transferred — things like real estate and most bank accounts — while a secondary will covers assets that typically don't need probate, such as shares in a private company. Because Estate Administration Tax is calculated on the value of the estate that actually goes through probate, keeping certain assets out of the primary will can reduce that tax exposure. This structure has been used in Ontario for years and remains lawful when properly drafted.

The Core Risk: Overlap and Accidental Revocation

The entire strategy depends on each will clearly stating what it does — and does not — cover, and clearly stating that it does not revoke the other will except as to the specific assets it deals with. Ontario's rules around how a later will revokes an earlier one are not automatically limited; a will that doesn't carefully carve out its own scope can end up revoking the other document entirely, or revoking gifts the person never intended to touch.

When that happens, the result is not simply an inconvenience. It can mean an asset that was supposed to be dealt with under the secondary will is now unaddressed, or that both wills purport to deal with the same asset in different ways, forcing the estate trustee — and potentially a court — to sort out which document controls.

Common Drafting Mistakes We See

1. A revocation clause that's too broad. The primary will's standard "I revoke all former wills" language, used without a carve-out, can accidentally revoke the secondary will it was meant to work alongside.
2. The same asset described in both wills. Without careful drafting, an asset can end up mentioned in both documents, creating ambiguity about which will actually governs it.
3. Executor or guardian appointments split awkwardly. Naming different estate trustees in each will, without a clear explanation of how they are meant to work together, invites confusion and potential conflict between them.
4. Wills signed on different dates without cross-referencing. If the two wills aren't drafted and reviewed together, later changes to one can drift out of alignment with the other.
5. A codicil added to only one will. Amending one document later, without revisiting the other, can reopen exactly the overlap and revocation problems the original drafting was designed to avoid.

What Happens If the Wills Conflict After Death

When an estate trustee discovers the two wills don't line up cleanly, the practical result is delay: legal advice needs to be obtained, and in more serious cases, a court application may be needed to interpret which document governs a disputed asset. This adds time and cost to exactly the kind of estate that a multiple-wills strategy was meant to make more efficient — the opposite of the intended result.

A Checklist for a Clean Multiple-Wills Plan

• [ ] Each will explicitly states which assets it covers
• [ ] The revocation clause in each will is limited to that will's own scope, not a blanket revocation of all prior wills
• [ ] No single asset is described or dealt with in both documents
• [ ] Executor appointments are coordinated, with a clear explanation if different people are named
• [ ] Both wills are reviewed together whenever either one is updated
• [ ] A lawyer familiar with both documents handles any future changes

Updating Multiple Wills Later

A codicil — a document that amends an existing will — must meet the same signing and witnessing formalities as the will it changes. When you're working with two wills, a change that seems to affect only one of them (a new beneficiary, a change in executor) often has implications for the other. Any update should be reviewed against both documents together, not treated as an isolated edit to whichever will seems most relevant at the time.

Frequently asked questions