Common-Law Property Rights in Ontario

No Automatic Equalization for Common-Law Partners

Ontario's Family Law Act gives married spouses a right, in most cases, to an equalization of net family property when a marriage ends — broadly, comparing what each spouse was worth at marriage and at separation, and requiring an equalizing payment so both spouses share equally in the increase in value built up during the marriage. This statutory scheme applies only to spouses who were legally married.

Common-law partners in Ontario do not have this automatic right, regardless of how long they lived together, whether they had children together, or how the household's finances were organized. Property generally belongs to whoever's name is on it — on title for real estate, or as the account holder for savings and investments — unless a partner can establish a separate legal basis for a claim. This is one of the most consequential, and most commonly misunderstood, differences between marriage and common-law status in Ontario. For a broader look at how common-law relationships are treated across property, support, and parenting, see Common-Law Relationships in Ontario. The rest of this guide focuses specifically on what a common-law partner can do about property when there is no automatic equalization to rely on.

Unjust Enrichment: The Basic Idea

Because the Family Law Act's equalization scheme does not reach common-law partners, courts instead fall back on a general area of law that predates, and exists outside, family law entirely: the law of unjust enrichment. It is not a family-law-specific concept — the same basic doctrine can apply between business partners, roommates, or family members in completely unrelated disputes.

In a common-law relationship context, the idea is that where one partner has gained a benefit — money, an interest in property, or being spared an expense they would otherwise have had to pay — while the other partner gave something up to make that possible, and there is no legal reason the first partner should get to keep the full benefit, a court can step in to correct the imbalance. Unjust enrichment claims are generally fact-heavy: success tends to turn on what each partner can actually show about their financial and non-financial contributions over the course of the relationship, not on how long the couple lived together alone.

The Elements of an Unjust Enrichment Claim

Canadian courts have generally organized an unjust enrichment claim around three elements that a claimant must establish:

• An enrichment: the other partner received a benefit — for example, a growing equity interest in a home, or the value of unpaid work.
• A corresponding deprivation: the claimant gave up something of comparable value to produce that benefit, such as money, labour, or foregone career opportunities.
• No juristic reason for the enrichment: there is no legal basis — such as a contract, a gift, or another recognized category — that would justify the other partner keeping the benefit without compensating the claimant.

All three elements generally need to be established; missing any one of them can be fatal to the claim. Because of this, gathering concrete records — bank statements, receipts, correspondence, and a clear timeline of who paid for what — matters a great deal in these cases, arguably more than in a married spouse's equalization claim, where entitlement does not depend on proving individual contributions in the same way.

Constructive Trust as a Remedy

Establishing unjust enrichment answers the question of whether a wrong occurred; it does not by itself decide what the claimant gets. Courts have generally treated a monetary award — compensating the claimant for the value of their contribution — as the default remedy.

In some cases, however, a monetary award is considered inadequate, particularly where the claimant's contributions can be clearly linked to a specific property, such as a home they helped pay for, maintain, or improve, and where money alone would not fairly capture what was given up. In those circumstances, a court may instead impose a constructive trust, recognizing that the claimant holds an actual ownership interest in that property, generally sized to reflect the proportion their contributions represent. A constructive trust is a remedy a court chooses to grant in appropriate cases — it is not an automatic outcome of every successful unjust enrichment claim.

The "Joint Family Venture" Concept

A significant development in this area came from the Supreme Court of Canada's 2011 decision in Kerr v. Baranow, which addressed how unjust enrichment claims should be assessed in long-term relationships where partners had pooled their efforts and finances over many years, rather than making one identifiable contribution to one identifiable asset.

The Court described these situations using the concept of a "joint family venture" — a relationship where both partners worked together toward common goals, integrated their finances and efforts, and generally lived and behaved as an economic unit, even without marrying. Courts look at factors including mutual effort, economic integration, actual intent to share in accumulated wealth, and the priority the couple placed on the family as a whole. Where a joint family venture is found, and it can be shown that the accumulation of wealth during the relationship is linked to that joint effort, a court can assess the claimant's share by looking at the overall wealth generated during the relationship, rather than requiring them to trace their exact contribution to one specific asset — often a more realistic approach for long-term relationships where money, labour, and time were pooled rather than tracked.

What Kind of Contributions Can Count

Because these claims depend on evidence rather than a formula, it helps to understand the types of contributions Ontario courts have generally been willing to consider, either alone or as part of a joint family venture:

• Direct financial contributions: mortgage or rent payments, renovation costs, or funds put toward acquiring a property.
• Indirect financial contributions: covering household expenses or debts that freed up the other partner's income or assets for something else.
• Unpaid domestic labour and child-rearing: work that allowed the household to function and, in some cases, allowed the other partner to build a career, business, or asset base.
• Contributions to a partner's business or career: unpaid work in a family business, or support that enabled the other partner's income growth.

A contribution on its own is rarely enough — it generally needs to be connected, with evidence, to the specific enrichment being claimed. This is why documentation collected during the relationship, not reconstructed afterward from memory, tends to matter so much in these cases.

Protecting Yourself With a Cohabitation Agreement

Because unjust enrichment and constructive trust claims are generally more uncertain, evidence-intensive, and expensive to pursue than a married spouse's equalization claim, many common-law couples choose to set their own property rules in advance through a cohabitation agreement. A properly signed domestic contract can specify how property will be divided, how contributions will be tracked or treated, and whether either partner will make a support payment — generally reducing or eliminating the need to rely on general equitable doctrines if the relationship ends.

A cohabitation agreement cannot decide parenting arrangements, which are assessed separately based on the best interests of the child at the relevant time, but for property specifically, it is generally the most direct way for common-law partners to obtain the kind of certainty that married spouses get automatically through equalization.

How These Claims Are Generally Pursued

There is no special standalone process for an unjust enrichment or constructive trust claim — it is generally raised as part of a family court application, the same way a common-law partner might address support or parenting issues. A general outline looks like this, though your own steps may vary:

1. Document the relationship and separation date

   Establishing when cohabitation started and ended can matter for the overall timeline of contributions.

2. Gather financial evidence

   Bank records, receipts, mortgage statements, and anything showing who paid for what, and when.

3. Identify the property or benefit in question

   A specific home, business, or asset the claim will focus on, or the relationship's overall accumulated wealth if a joint family venture is being argued.

4. Get professional advice on the strength of the claim

   Outcomes depend heavily on the specific facts, so an early assessment can help set realistic expectations.

5. Start or respond to a family court application

   See getting started in family court for a general orientation to the process.

6. Consider settlement before trial

   Many property claims between common-law partners are resolved through negotiation or another dispute-resolution process rather than a full trial.

Because a claim's strength depends so heavily on evidence, delaying can make it harder to reconstruct what actually happened financially during the relationship — another reason early advice tends to be valuable.

Frequently Asked Questions