Common-Law Relationships in Ontario: Rights and Property

In Ontario, living together for years does not give common-law partners the automatic right to split property the way marriage does; that right belongs to married spouses under the Family Law Act, and an unmarried partner's claim to shared property has to be proven separately, through the courts.

The Misconception That Trips Up Most Ontario Couples

Many people assume that after a few years of living together, they have "common-law" rights equivalent to marriage. In Ontario, that assumption is wrong on the point that matters most: property.

When a married couple divorces, the Family Law Act (FLA) applies equalization of net family property: each spouse's net worth gained during the marriage is calculated, and the spouse with more pays the other roughly half the difference. This is automatic, and it does not matter whose name is on the assets.

That equalization scheme applies only to married spouses. The FLA's Part I property provisions, including equalization, use a definition of "spouse" limited to two people who are married to each other (or who married in a form that is voidable or void, entered in good faith). Common-law partners, no matter how long they cohabited, fall outside that definition and get no equalization claim at all.

This is the single most important thing to understand about ending a common-law relationship in Ontario: there is no 50/50 split by default. Whatever remedy an unmarried partner has must be built from other legal doctrines, discussed below.

"Common Law" Is Not One Legal Status. It Depends What You're Asking

Ontario law does not have a single test for "are we common law." The answer changes depending on why you're asking, and getting this wrong is where a lot of confusion starts.

For Spousal Support: The Family Law Act Test

Support obligations are covered separately, under FLA Part III. Under section 29, you are treated as a "spouse" for support purposes if you are not married to your partner and either:

• You have cohabited continuously for a period of not less than three years, or
• You are in a relationship of some permanence and are the parents of a child together (natural or adopted).

Meeting this test does not create a property claim. It only opens the door to a possible spousal support claim, and support still has to be justified on its own terms (need, compensation for economic disadvantage from the relationship, or an agreement). For how that support might be calculated once entitlement is established, see our overview of spousal support in Canada and the Canada spousal support calculator.

For Tax Purposes: A Different Clock Entirely

The Canada Revenue Agency uses its own definition for tax and benefit purposes, and it is not the same test. The CRA generally treats a couple as common-law after 12 months of continuous cohabitation, or sooner if they have a child together. That is a federal tax rule, not a provincial family-law one, and it has no bearing on whether an Ontario court will order support or divide property. Don't assume that because the CRA considers you common-law, the FLA does too, or vice versa.

For Property: There Is No Threshold At All

This is the part people miss. Because equalization under the FLA never applies to unmarried couples, there is no cohabitation period, however long, that turns on an automatic property right. Ten years together does not create it. Neither does twenty. Property has to be pursued through a different legal route entirely.

Property When You're Not Married: Unjust Enrichment, Not Equalization

If a common-law relationship in Ontario ends and one partner believes property was unfairly built up in only the other partner's name, their claim is not to "half the property." It is a claim in unjust enrichment, and if the relationship functioned as an economic partnership, potentially a constructive trust over specific property based on a joint family venture.

The leading case is Kerr v Baranow, 2011 SCC 10, where the Supreme Court of Canada confirmed the modern framework for these claims after a common-law relationship ends. To succeed, the claiming partner generally has to show:

1. The other partner was enriched (received a benefit),
2. The claiming partner suffered a corresponding deprivation, and
3. There is no juristic reason for that enrichment, meaning no contract, gift, or other legal basis that explains it.

Where the couple's lives were genuinely economically integrated (pooled finances, one partner giving up career opportunities for the household, shared decision-making that prioritized the family as a unit), the court can find a joint family venture and award a share of the wealth accumulated proportionate to each partner's contribution, rather than treating each asset in isolation.

This is a real remedy, but it is not automatic. It requires evidence, legal argument, and a judge's finding, which is very different from the FLA's formula-based equalization that married spouses get simply by virtue of the marriage ending.

The Family Home: Also Married-Spouses-Only

The FLA gives special protection to the matrimonial home, the residence the couple was living in at separation. A married spouse has an automatic right to stay in that home regardless of whose name is on title, and the home is treated differently in the equalization calculation (its full value is generally included, without deducting its value on the date of marriage).

None of this applies to common-law partners. If you are not married, your right to remain in a home you shared with your partner depends on ordinary property law: whether your name is on title or the lease, whether you can show a beneficial interest through a claim like the ones described above, or what any cohabitation agreement says. There is no special "common-law matrimonial home" protection in Ontario.

If Your Common-Law Partner Dies Without a Will

Death raises the same misconception in a different form. Under Ontario's Succession Law Reform Act (SLRA), the rules for who inherits when someone dies intestate (without a valid will) use the same married-only definition of "spouse" that governs property equalization. A common-law partner, regardless of how many years the couple lived together, is not an automatic heir. The estate passes instead to children, or if there are none, to other blood relatives, under the SLRA's statutory formula, with the surviving common-law partner receiving nothing by default.

A surviving common-law partner is not left with no options, though. Part V of the SLRA allows a dependant's support claim: a person the deceased was supporting, or was legally obligated to support, immediately before death can apply to the court for support from the estate. For this purpose, "spouse" is defined the same way it is for support under the FLA (three years of cohabitation, or a relationship of some permanence with a shared child), so many common-law partners qualify to bring the claim. But it is a claim that has to be made and proven based on dependency, not an automatic inheritance. See our guide to dying without a will in Canada for how intestacy works more broadly.

One Notable Exception: Workplace Pensions

There is one area where Ontario treats common-law partners much like married spouses: registered pension plans. Under the Pension Benefits Act, a surviving "spouse" eligible for a mandatory joint-and-survivor pension or pre-retirement death benefit includes a common-law partner who meets the same three-year (or child-plus-permanence) test used for support. That makes pensions a meaningful exception to the general rule that Ontario common-law partners get nothing automatically.

Married vs. Common-Law in Ontario, Side by Side

Why a Cohabitation Agreement Matters So Much in Ontario

Because the default rules give common-law partners so little automatic protection on property, a cohabitation agreement is the tool that actually lets a couple decide how they want to be treated. A properly drafted cohabitation agreement can:

• Set out how property will be divided if the relationship ends, effectively opting into (or customizing) something closer to the equalization regime married spouses get automatically.
• Address spousal support in advance, including waiving it or capping it, subject to the same fairness scrutiny courts apply to any domestic contract.
• Clarify what happens to a shared home.
• Reduce the odds of an expensive unjust enrichment lawsuit later, since the couple's intentions are documented rather than reconstructed after the fact from years of financial history.

To be enforceable, a domestic contract generally needs to be in writing, signed, and witnessed, with each partner making full financial disclosure to the other. Courts have set agreements aside where a party hid assets or where the agreement was fundamentally unfair on the facts, so independent legal advice for each partner before signing is strongly recommended. For more on how these agreements work and what makes them hold up, see our guide to separation agreements in Canada.

Ontario is also only one part of the picture. Cohabitation thresholds and the rights that come with them vary significantly by province, from British Columbia's more generous approach to Quebec's, where de facto (common-law) couples have no statutory right to spousal support at all. For a province-by-province comparison, see common-law relationships across Canada, and for the general hub on this topic, Canadian family law.

Disclaimer: This article provides general information about Ontario family law and is not legal advice. Family law outcomes depend on the specific facts of each relationship. Consult a licensed Ontario family law lawyer about your situation.

Frequently Asked Questions

Do common-law partners in Ontario split property 50/50 like married couples?

No. Equalization of net family property under the Family Law Act applies only to married spouses. A common-law partner who wants a share of property accumulated during the relationship has to bring a separate claim, typically unjust enrichment or a constructive trust based on a joint family venture, as set out in Kerr v Baranow.

How long do you have to live together to be common law in Ontario?

It depends on the purpose. For spousal support under the Family Law Act, the threshold is 3 years of continuous cohabitation, or less if you and your partner are the parents of a child together and have a relationship of some permanence. For property, there is no threshold at all, since automatic property division never applies to unmarried couples regardless of how long they lived together.

Is the CRA's common-law definition the same as Ontario's family law definition?

No. The Canada Revenue Agency generally treats a couple as common-law for tax purposes after 12 months of cohabitation, or sooner with a shared child. That federal tax definition is separate from the Family Law Act's 3-year support threshold, and neither one creates a property right.

Can a common-law partner stay in the home if the relationship ends?

Not automatically. The Family Law Act's special matrimonial home protections, including the right to remain in the home regardless of whose name is on title, apply only to married spouses. A common-law partner's right to stay depends on ordinary property or lease rules, or on a cohabitation agreement.

What happens if my common-law partner dies without a will in Ontario?

You are not an automatic heir. Ontario's intestacy rules under the Succession Law Reform Act use the same married-only definition of spouse used for property equalization, so a surviving common-law partner does not inherit by default. You may be able to bring a dependant's support claim under Part V of the Act if you can show you were financially dependent on the deceased.

Does a cohabitation agreement actually help in Ontario?

Yes. Because the default law gives common-law partners very little automatic protection on property, a written, signed, and witnessed cohabitation agreement, made with full financial disclosure from both partners, is the main way a couple can set their own rules for property and support instead of relying on an unjust enrichment claim after the fact.