The most common will mistakes in Ontario are letting a beneficiary witness the will, never updating it after a marriage or separation, ignoring assets that pass outside the will, naming the wrong executor, relying on a handwritten or online will, and putting off a will altogether. Each one can quietly cancel a gift, push your estate into court, or hand your assets to someone you never intended.
A will looks simple, so people assume that once they sign something their wishes are locked in. In our practice the wills that cause the most trouble are the ones a lawyer never checked, because the problems only surface after the person has died, when nothing can be fixed.
About half of Canadian adults have no will at all, according to the Angus Reid Institute in 2023, and many who do have one signed it years ago and never looked at it again. This guide walks through the mistakes we see most often in Toronto and across Ontario, what each one costs your family, and how to avoid it. If you would rather talk it through, our wills and estates lawyers in Toronto offer a free 15 minute consultation.
What Makes a Will Valid in Ontario?
Ontario wills are governed by the Succession Law Reform Act. To make a standard will you must be at least 18, you must understand what you own and who depends on you, and you must sign the will at its very end in front of two witnesses who are both watching at the same time. Both witnesses then sign while you watch. Miss any of these steps and the will can fail.
A few rules trip people up most often.
- Your two witnesses must not be people who inherit under the will, and must not be married to anyone who inherits under it.
- Ontario does allow a handwritten will, called a holograph will, that is written entirely in your own handwriting and signed, with no witnesses. It is legal, but it carries real risk.
- Signing over video is now a permanent option, but at least one witness has to be a licensed Ontario lawyer or paralegal, everyone signs the same will in counterpart, and the signatures must be in ink.
Since January 1, 2022 the Superior Court of Justice can save a will that misses a technical step, under section 21.1 of the Act. That power is a safety net, not a plan. It means your family pays for a court application to prove what you meant, so the goal is always to get the will right the first time.
Mistake 1. Letting a Beneficiary or Their Spouse Witness Your Will
If someone who inherits under your will signs as a witness, the will usually stays valid, but their gift is wiped out. Section 12 of the Succession Law Reform Act voids any gift to a witness, and to the spouse of a witness. So the daughter you left your home to can lose the home if she or her husband signed as a witness.
A court can restore the gift if your family proves there was no pressure on you when you signed, but that is a separate court motion with its own legal fees and delay, and it is not guaranteed. This is the single most common signing error we correct. The fix costs nothing. Choose two adult witnesses who get nothing under the will and who are not married to anyone who does.
Mistake 2. Assuming Marriage, Separation, or Divorce Sorted Itself Out
Ontario changed these rules on January 1, 2022, and a lot of online guidance still has them wrong. This is where we see people relying on a will that no longer does what they think.
Marriage
For marriages on or after January 1, 2022, getting married no longer cancels your existing will. The catch is that the change is not retroactive. If you married before that date, the older rule still applies to that marriage, and a will you signed before the wedding was cancelled by it unless the will said it was made in contemplation of the marriage. Many people in this position believe they still have a valid will. They do not, and only a review will catch it.
Separation and divorce
Divorce has always cancelled gifts to a former spouse. Since January 1, 2022 separation does the same. If you are separated from your spouse when you die, and you meet the test in the Act, which is usually living apart for three years because of a breakdown, or a separation agreement, or a court order, then any gift to that spouse and any appointment of them as your executor is cancelled, and the will reads as if they died before you. A separated spouse also loses the right to inherit if you leave no will at all.
Common law partners
Moving in with a new partner does not change or cancel your will. A common law partner also does not automatically inherit if you have no will. They can only ask the court for support as a dependant. The practical takeaway is simple. Review your will after any marriage, separation, divorce, or new long term relationship.
Mistake 3. Forgetting the Assets That Pass Outside Your Will
Your will does not control everything you own. Registered accounts with a named beneficiary, such as an RRSP, a RRIF, or a TFSA, life insurance with a named beneficiary, and property you hold as joint tenants with right of survivorship all pass straight to the named person or the surviving owner, no matter what your will says.
We see two costly versions of this. In the first, a will leaves everything equally to three children, but the only real asset is a home the parent put into joint names with one child, so that child keeps the house and the other two receive almost nothing. In the second, an old beneficiary form still names a former spouse on a pension or an insurance policy, and that money goes to the ex even though the will says otherwise. Update your beneficiary designations and your property ownership so they match your will, and tell your lawyer about every account.
Mistake 4. Naming the Wrong Executor, or No Backup
Your executor, called your estate trustee in the Act, gathers your assets, pays your debts and taxes, and distributes what is left. The wrong choice creates conflict, cost, and delay. The errors we see most are naming someone who lives outside Canada, which can force the estate to post a bond, naming a person who is already in conflict with your beneficiaries, and naming only one person with no alternate.
If your only named executor dies before you or cannot act, and you named no backup, someone has to apply to the court to be appointed before the estate can move. Name a capable and trusted executor, name at least one alternate, and ask both people before you sign so the role does not surprise them.
Mistake 5. Trying to Cut Out a Dependent
You can leave your estate to whomever you choose, but Ontario law does not let you leave a dependant with nothing. Under the Succession Law Reform Act a spouse, a child, a parent, or a sibling who relied on you for support can apply to the Superior Court of Justice for support from your estate, even when your will gives them nothing.
These claims carry deadlines and they can freeze an estate while the court sorts them out. If you plan to leave out someone who depended on you, talk to a lawyer first about whether the law allows it and how to lower the risk of a challenge. A clear, well drafted will and the right supporting documents make a dispute far less likely.
Mistake 6. Relying on a Handwritten or Online Will
A handwritten or store bought will can be valid, and it is also where we see the most expensive mistakes. A holograph will has to be written entirely in your own hand and signed. Print a template, fill in the blanks by hand, and you have created something that is neither a proper witnessed will nor a valid holograph will, so it can fail completely.
Online kits often miss the residue clause, the part that deals with whatever is left after your specific gifts, use wording that is open to more than one meaning, or get signed with the wrong number of witnesses. When the wording is unclear, your family ends up in court asking a judge what you meant, and the few hundred dollars you saved on a lawyer can turn into thousands in legal fees and probate delays. A simple will prepared properly is inexpensive insurance against all of this.
Mistake 7. Putting Off a Will Altogether
If you die without a will in Ontario, the Succession Law Reform Act decides who inherits, and the result is rarely what people expect. The court has to appoint an administrator, which can mean a bond and added cost, and you can read the steps on the Ontario government probate page. Your assets are then divided by a fixed formula.
If you have a spouse and children, your spouse receives the first $350,000, called the preferential share for deaths on or after March 1, 2021, and the rest is split between your spouse and your children by formula. A common law partner inherits nothing under these rules. A minor child’s share is held by a government office until the child turns 18, then paid out in full whether or not the young adult is ready for it. A will lets you choose your executor, name a guardian for minor children, and decide who receives what, instead of leaving it to a formula.
Common Will Mistakes and What They Cost
This table sums up the mistakes above and the practical consequence of each. Use it as a quick check against your own will.
| Mistake | What goes wrong | Practical consequence |
| Beneficiary as witness | Section 12 voids the gift to that witness | Your chosen heir loses the gift unless a court restores it |
| Old will after marriage before 2022 | The marriage cancelled the earlier will | You may have no valid will and not know it |
| No update after separation | Gifts and roles for the spouse are revoked | Your estate plan no longer reflects your wishes |
| Ignoring non will assets | Designations and joint ownership override the will | Money goes to the wrong person regardless of the will |
| Wrong or sole executor | No one is able or willing to act | Court application, bond, delay, and family conflict |
| Disinheriting a dependant | A dependant claims support from the estate | Litigation and a frozen estate |
| Handwritten or online will | Invalid form or unclear wording | The will fails or your family goes to court over meaning |
| No will at all | The Act applies a fixed formula | Strangers to your wishes inherit and a partner may get nothing |
Frequently Asked Questions
Does my will need to be notarized in Ontario?
No. A will is valid once you sign it and it is properly witnessed, and notarization is not required. What helps later is an affidavit of execution, a sworn statement from a witness that confirms the signing, because it speeds up probate. Our notary and commissioner of oaths can prepare one for you. Learn more about our notary services
Can my spouse or child witness my will?
They can witness it, but they will lose whatever you left them under section 12 of the Succession Law Reform Act unless a court later restores the gift. Use two witnesses who inherit nothing and who are not married to anyone who does.
Does getting married cancel my will in Ontario?
Not for marriages on or after January 1, 2022. A marriage before that date did cancel an earlier will unless the will stated it was made in contemplation of that marriage. If you married before 2022 and never updated your will, have it checked.
What happens to my will if I separate but do not divorce?
If you are separated when you die and you meet the test in the Act, the gifts to your spouse and their appointment as your executor are cancelled, and the will reads as if they died before you. The Act usually treats you as separated after three years apart, or once you have a separation agreement or court order.
Can I leave someone out of my will completely?
You choose your beneficiaries, but a person who relied on you for support can apply to the court for support from your estate. Get advice before you disinherit a dependant, because a clear plan lowers the risk of a challenge.
Is a handwritten will valid in Ontario?
Yes, if it is written entirely in your own handwriting and signed by you, which the law calls a holograph will. A typed will, or a printed form you only partly fill in by hand, does not qualify and needs two proper witnesses.
The information provided above is of a general nature and should not be considered legal advice. Every transaction or circumstance is unique, and obtaining specific legal advice is necessary to address your particular requirements. Therefore, if you have any legal questions, it is recommended that you consult with a lawyer.
