Common Law in Ontario: Property & Support

This article is general Ontario family law information, not legal advice. If you are in a common law relationship or have recently separated from one, get advice on your specific facts before acting on general guidance.

Common law in Ontario is not simply an unmarried couple living together: it is a legal status that arises only when specific statutory criteria are met. Under the Family Law Act, for example, an unmarried partner qualifies as a “spouse” for support purposes only after three years of continuous cohabitation, or sooner where the couple are in a relationship of some permanence and have a child together. Despite the popular phrase, there is no “common law marriage” in Ontario: no amount of living together converts a couple into married spouses. The definition also changes depending on which statute applies, and the rights that come with common law status differ from those of married spouses. The single biggest difference is property: common law partners have no automatic right to equalization under the Family Law Act.

When Are You Considered Common Law in Ontario?#

There is no single answer, because Ontario uses different definitions of common law depending on the statute in question. For the two subjects this article covers, spousal support and division of property, the starting point is the Family Law Act.

For spousal support under the Family Law Act, you qualify as a “spouse” if you and your partner have cohabited continuously for at least three years, or if you have cohabited in a relationship of some permanence and have a child together (FLA, s. 29).

For property division under the Family Law Act, common law partners are excluded from Part I equalization rights. Only married spouses qualify, no matter how long the cohabitation lasted.

Other areas of law draw the line in their own places. Income tax law and estate law each use their own definitions of a common law spouse, with different thresholds and different consequences; those rules go beyond the scope of this article. Do not assume that meeting the definition under one statute means you meet it under another.

Common Law Property Rights in Ontario#

This is where common law and married couples differ most. Married spouses in Ontario have a statutory right to equalize their net family properties under Part I of the Family Law Act (ss. 4-16), but common law partners do not.

That means if one partner owns the home, the car, and the investments while the other partner owns little, there is no automatic way to split the difference. The starting point is that the titled owner keeps what is in their name, even after decades of living together.

But that is only the starting point. Ontario courts have developed equitable remedies that let a common law partner recover a share of property even without a statutory right to equalization.

The main route is a claim in unjust enrichment, with a constructive trust available as one of its remedies. The Supreme Court of Canada set out the modern framework in Kerr v. Baranow, 2011 SCC 10, at paras 31-47. The three elements of an unjust enrichment claim are:

1. An enrichment of one partner
2. A corresponding deprivation of the other
3. No juristic reason (no legal justification) for the enrichment

In Kerr v. Baranow, the Court also recognized the joint family venture concept (at paras 87-89). Where the evidence shows the parties were engaged in a joint family venture and the claimant’s contributions are linked to the wealth it generated, the court can award a share of that wealth in proportion to those contributions. The Court identified four signposts for the analysis: mutual effort, economic integration, the parties’ actual intent, and the priority of the family in their decisions (para 89). Before Kerr, valuing these claims in a principled way was difficult.

The doctrine of constructive trust in common law relationships traces back to the Supreme Court’s decision in Pettkus v. Becker, [1980] 2 SCR 834, which first recognized that a common law partner’s contributions could give rise to a proprietary interest through a constructive trust. Building on that foundation, Peter v. Beblow, [1993] 1 SCR 980 confirmed that domestic services can satisfy the elements of unjust enrichment. Homemaking and childcare count as both the enrichment and the corresponding deprivation. A constructive trust is not automatic: the claimant must show both that a monetary award would be insufficient and that their contributions have a “sufficiently substantial and direct” link to the specific property claimed (Kerr at paras 50-52).

Unjust enrichment is not the only equitable claim. A resulting trust may arise where one partner gratuitously transfers property into the other’s name, or where both partners contribute to the purchase of property that is held in only one name (Kerr at para 17). In Kerr, the Court retired the “common intention” resulting trust but confirmed that traditional resulting trust principles “may well have a role to play in the resolution of property disputes between unmarried domestic partners” (paras 15 and 29). In practice, most claims now proceed in unjust enrichment, but a resulting trust can matter where the dispute centres on who paid for a specific asset.

A Practical Example#

Consider Priya and James. They lived together for 14 years. James owned the home before they met. Priya contributed to the mortgage and renovations and took primary responsibility for their two children while James built his business. They never married.

When they separate, Priya has no equalization claim, but she may have a strong unjust enrichment claim. If the evidence shows the couple operated as a joint family venture, Priya may be entitled to a share of the wealth built during the relationship, including the increase in value of the home and the business. The size of that share depends on proof of mutual effort, financial integration, and actual contribution.

These claims can sometimes produce outcomes that resemble equalization. But the process is different, the burden of proof is different, and the outcome is far less certain. In my experience, unjust enrichment claims are among the most evidence-heavy family law disputes. A cohabitation agreement is usually a far better path than relying on a court to sort things out after the fact.

For more on how common law property claims work, see our page on the division of property for common law couples.

Spousal Support for Common Law Partners in Ontario#

Common law partners in Ontario can claim spousal support. The test is the same threshold under section 29 of the Family Law Act: three years of continuous cohabitation, or cohabitation in a relationship of some permanence with a child together.

Meeting the threshold gives a partner standing to apply; entitlement still has to be established on compensatory, needs-based, or contractual grounds. From there the analysis is broadly similar to what applies to married spouses. The court looks at the length of the relationship, the roles each party played, the financial impact of the breakdown, and the relative means and needs of each person. Once entitlement is established, courts use the advisory Spousal Support Advisory Guidelines (SSAG) the same way to assess amount and duration.

One practical difference: because common law partners cannot equalize property, support sometimes carries more weight in the overall outcome. A married couple might resolve a financial gap through property equalization, but a common law couple may lean more heavily on support. I see this often where one partner built up wealth while the other’s earning capacity declined.

For a detailed discussion of how spousal support works in Ontario, see our spousal support guide.

Cohabitation Agreements for Common Law Couples in Ontario#

A cohabitation agreement is the most direct way for common law partners to set out their property and support rights in advance. These are domestic contracts under s. 53 of the Family Law Act. Properly made, they are generally enforceable, but they are not immune from review: a court can set aside all or part of one under s. 56(4), and can override a support provision or waiver in limited circumstances under s. 33(4).

A cohabitation agreement can address:

• who owns what property and how it will be divided on separation
• whether spousal support will be payable, and on what terms
• how debts will be allocated
• specific provisions for the family home

For the agreement to hold up, each party should have independent legal advice, and there should be full financial disclosure. The agreement must be in writing, signed by both parties, and witnessed (FLA, s. 55(1)). Agreements made without independent legal advice or proper disclosure are vulnerable to being set aside.

Timing matters. The best time to put a cohabitation agreement in place is before or early in the relationship. Many couples wait until the relationship is well established, which makes the conversation harder but does not make it less useful. I would rather see a couple sign an agreement five years in than have nothing at all after fifteen.

Common Law Separation in Ontario: Dates and Deadlines#

For married couples, the separation date drives equalization: it usually sets the valuation date. For common law couples, there is no equalization, so the separation date matters in a different way.

For spousal support, you may run into an outdated warning: that common law partners must claim support within two years of separation or lose the right. That deadline no longer exists. The Family Law Act’s former limitation provision, s. 50, was repealed, and the Limitations Act, 2002, s. 16(1)(c) now provides that there is no limitation period for a proceeding to obtain support under the Family Law Act.

Pinning down when common law partners “ceased to cohabit” is not always clear. Couples sometimes separate step by step, pulling apart their finances while still living under the same roof. Courts look at objective signs such as shared meals, social life as a couple, sexual relations, financial ties, and sleeping arrangements.

Support is only one claim, and other claims carry their own clocks. Limitation periods for equitable property claims depend on the claim and the remedy sought. In McConnell v. Huxtable, 2014 ONCA 86, the Court of Appeal held that a constructive trust claim to land falls under the ten-year limitation period in s. 4 of the Real Property Limitations Act (at paras 40-42), while equitable claims generally are otherwise governed by the Limitations Act, 2002 and its two-year basic period, with the clock ordinarily not starting until the parties have separated with no prospect of resuming cohabitation (at paras 48-54). Get advice promptly rather than assuming the no-deadline support rule covers everything.

No deadline does not mean no urgency. Courts weigh delay when they set a support start date or decide how far back support should reach, and the evidence that proves cohabitation and contributions (statements, receipts, witnesses’ memories) gets harder to assemble every year. Waiting can shrink the retroactive part of a claim and make the rest harder to prove, even though it no longer bars the claim.

Frequently Asked Questions#

Last updated: July 2026

If you have questions about common law rights in Ontario, contact Krol & Krol for a consultation.