So, you’re unhappy with the last will and testament of a family member, or someone from whom you reasonably expected to inherit……

Legally, any person can challenge the validity of a Will, but there are only certain grounds to do so.

If you do not qualify within one or more of these recognized grounds, the Court is unlikely to allow your claim to proceed to what is often very costly and protracted litigation proceedings.

Will disputes are on the rise in Ontario, unfortunately.

They are often characterized by emotional, bitter litigation, usually resulting in the respective lawyers financially gaining more so than the litigants themselves.

What are these grounds to challenge the validity of a Will in Ontario?

Lack of Testamentary Capacity

A testator (meaning the person making the Will) must have the necessary level of mental capacity in order to make a valid Will. Generally speaking, the testator must understand what a Will is and must understand, at least, the general extent of their property. They must also remember and have given consideration to their close relatives to whom they would usually be expected to leave their estate. They must also not be under any delusions that would affect their Will.

It is important to note that the threshold for testamentary capacity is not particularly high. A testator does not have to be fully capable with respect to the management of the property. Rather, so long as the testator has a general understanding of what they own, this will be sufficient.

Likewise, it is important to note that in Ontario, a testator is generally allowed to cut adult children out of a Will (so long as they are not financially dependent on the testator – see below). The test for capacity only requires that the testator remains aware of their children and makes a conscious decision as to whether or not to leave them anything.

Lack of Knowledge and Approval

In addition to having the proper level of capacity, a testator must also actually be aware of what is in their Will. This does not mean that the testator needs to fully understand and appreciate the nuance of each and every clause in the Will (which may be drafted in dense “legalese”); but if the testator signed their Will without being fully aware of the general scheme set out in it, then there is a basis on which to contest the Will.

Will Not Validly Executed

Another ground for challenging a Will is if the proper procedure has not been followed for making a valid Will. To be valid, a Will must be in writing and signed by the testator and two witnesses. The witnesses should not be beneficiaries, or else the gifts made to those beneficiaries acting as witnesses will be void.

If these requirements are not properly met, then the Will can be challenged.

However, it is important to point out that in Ontario, there is also a second, special way to make a valid Will, called a “holograph” Will. This is a Will written entirely in the testator’s handwriting, and signed by the testator.

Undue Influence

Undue influence occurs when someone exerts an inappropriate level of pressure on a testator, to the extent that the testator makes a Will that goes against their true wishes.

As an example, consider a situation in which a testator is very weak and frail and becomes entirely dependent on a friend to care for them. That caregiver may try to exploit the relationship of dependence in order to effectively force the testator to change their Will. If, as a result, the testator makes a Will that goes against their true wishes, then that Will is invalid. However, if the testator legitimately wants to change their Will to reward this caregiver, then this is not undue influence.

It is important to note that it is a very high bar to establish undue influence. In general, there is no prohibition against directly asking or pleading with someone to change their Will. This type of behaviour only crosses the line into undue influence when the testator feels forced to make a Will that they otherwise would not make.

Failure to Provide for Dependents

Finally, if a Will does not make sufficient provision for a dependent of the testator, then this dependent can bring a court application to receive ongoing or lump-sum support from the estate. In this context, a dependent includes someone whom the testator had a legal obligation to support (for example, a spouse or minor child), as well as someone whom the testator was actively supporting prior to their death, even if there was no strict obligation to do so.

This type of court application is not a direct challenge to the validity of the Will itself. Rather, it is an application seeking support to be paid “off the top” of the estate assets. The remaining estate assets would still be distributed as per the Will.


C. Crisman-Cox, Miller Thomson LLP


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