With shifting laws making estates harder to protect will your child lose their inheritance to an in-law?

Consider the case of Joan, a 73-year-old widow with a $1.5-million house and roughly $1 million in savings. Joan is currently drafting her will with one clear goal: She wants her entire $2.5-million estate to pass only to her son, Roger. Her goal is to give her estate to her son and and exclude his wife, in part, because Joan has never gotten along with her daughter-in-law. While Joan is fictitious, the situation is common and without advanced planning, any parent’s hard-earned wealth could easily be subject to a 50/50 split in a future divorce.

Drawbacks of a will

For most, a will is the primary tool for distributing property, yet 2026 data shows that 54% of Canadians still do not have a signed, up-to-date will (1). While a will is a necessary start, it is not a perfect tool.

For instance, if Joan left her son Roger her estate, those assets would be protected under provincial family-property laws (2). At this point, Joan’s wish — to exclude Roger’s wife from benefitting from Joan’s estate — could be enforced.

However, if Roger commingles his inheritance — such as depositing the funds into a joint bank account or using the money to pay down the mortgage on the family home — those funds may be considered marital property and subject to division (3).

Plus, in some provinces, a will can be challenged by family members who feel they were not provided for fairly. For instance, in British Columbia, the Wills, Estates and Succession Act (WESA) allows the court to alter a will if it does not make adequate provision for a spouse or child (4). This makes BC unique in Canada, as it is the only province where adult independent children can potentially sue to change the terms of a parent’s will.

Even if Roger keeps his inheritance separate, any increase in the value of that inheritance during the marriage can be considered family property, prompting courts to award a 50/50 split of the appreciation on the assets upon marital separation (5).

Regional shifts: Quebec’s new parental union

In Quebec, the rules for Joan would be even more distinct. Under the Civil Code of Quebec, the "family patrimony" — which includes family residences, furniture, and vehicles — is generally split equally upon death or divorce (6). While inheritances are technically excluded, they can become "crystallized" as a debt owed to a spouse if the money is used to improve family assets (7).

Crucially, as of 2026, Quebec has implemented the "Parental Union" (following Bill 56), which grants new inheritance and property rights to de facto (common-law) partners who have a child together (8). For the first time, these partners may inherit a portion of an estate even if there is no will, making it vital for parents to explicitly state their intentions to exclude certain parties (9).

Why it’s beneficial to put your estate in a trust

One of the most effective ways to protect your legacy is to leave your estate in a trust. A trust can legally protect your money and property while ensuring assets are distributed according to your wishes. With a trust, you appoint a trustee — someone who manages the assets on behalf of the beneficiaries.

To help you determine the best option, here are the main trusts currently in use in estate planning in Canada:

• Living trust (inter vivos trust): This takes effect while you are alive. In Canada, many living trusts are revocable, meaning they can be amended or cancelled, but this flexibility generally limits any asset-protection benefits. Living trusts involve ongoing administrative responsibilities, including annual trust tax filings. Depending on how the trust is structured, income earned in the trust may be taxed at the trust level or attributed back to you under Canada Revenue Agency (CRA) rules, which can increase complexity and costsbut this flexibility generally limits any asset-protection benefits (10).
• Irrevocable trust: Used for long-term planning, these assets are no longer legally owned by you, which may insulate them from certain creditor or family-law claims if structured correctly (10). However, irrevocable inter vivos trusts are subject to complex tax and reporting rules, and generally taxed at the highest marginal rate on retained income. Plus these trusts can involve significant setup and ongoing administration costs (11).
• Henson Trust: Commonly used when a beneficiary has a disability, this trust is designed to provide financial support after your death while preserving the beneficiary’s eligibility for means-tested government benefits, such as the Ontario Disability Support Program (ODSP). Plus, the trustee has absolute discretion over whether, when and how much income or capital is distributed to the beneficiary, which is key to maintaining benefit eligibility (12).
• Testamentary trust: Created through your will, this trust only takes effect after death. It is one of the most powerful ways to divorce-proof an inheritance, as assets held within a long-term trust are generally not considered family property and remain protected from a child's spouse (13).

Final thoughts

If you want your estate to stay with your children and not their spouses, a simple will might not offer enough control. Using the right kind of trust lets you set clear rules and protects the inheritance from relationship breakdowns or poor money management. To ensure your wishes are legally enforceable, work with an estate lawyer to draw up a trust that protects your legacy. In the end, it’s your legacy that you are leaving, not just your assets.

Article sources

We rely only on vetted sources and credible third-party reporting. For details, see our editorial ethics and guidelines.

Angus Reid Institute: 2026 Estate Planning Survey (1); Onyx Law Group: BC Inheritance Laws (2025/2026) (2, 4); Alves Law: Inheritance and Divorce in Ontario (3); Province of British Columbia: Family Law Act (5); Éducaloi: Property Included in the Family Patrimony (6); PSPLegal: Division of Family Assets in Quebec (7); Raymond James: The Parental Union Reshaping Quebec Families (8, 9); RBC Wealth Management: Understanding Living Trusts (10); Strategic Wealth Protection: Irrevocable Trusts in Canada (11); Planning Network: Henson Trust Basics (12); National Bank: Benefits of Testamentary Trusts (12); Invested MD: Protecting Inheritance from Divorce (13)