Common Law Separation in Ontario: A Guide to Mediation, Agreements, and Your Rights
For couples who lived together without getting married, the end of the relationship raises questions that are sometimes harder to navigate than a married couple’s separation. The law treats common-law partners differently than married spouses in important ways, particularly when it comes to property. Many people don’t learn what those differences are until they need to.
You may have seen the relationship called common law marriage, common law partnership, cohabitation, or just living together. In Ontario, the legal term is common-law spouses or unmarried cohabiting partners. Whatever you call it, the issues at separation are real: who keeps the house, how shared finances are unwound, what happens with the children, and whether one party owes the other support.
At Sage Harmony, we help common-law couples work through separation in mediation, the same way we work with married couples. We draft the separation agreement that records the terms, and we are insured for separation agreement drafting. Independent legal advice from each party’s own family lawyer before signing is recommended but not required.
If you’d like to talk through your situation, contact us to start the intake process. Or read below for a guide to how common-law separation works in Ontario.
Important: This page provides general information about common-law separation in Ontario. It is not legal advice. Sage Harmony does not act as legal counsel to either party. We recommend each party consider obtaining independent legal advice from their own family lawyer before signing any separation agreement.
Is There Such a Thing as Common Law Marriage in Ontario?
This is one of the most misunderstood areas of Ontario family law, so it’s worth being plain about.
Ontario does not have “common law marriage” in the formal sense. There is no point at which a cohabiting couple is automatically converted to married. The federal Civil Marriage Act and Ontario’s Marriage Act require a formal ceremony for two people to be legally married. Living together, even for decades, does not produce a marriage.
What Ontario does have is a legal category called common-law spouses (also called unmarried cohabiting partners or common-law partners) that triggers certain rights and obligations under provincial law once a couple has lived together long enough or had a child together. This is what most people mean when they say “common law for marriage” or “legal common law marriage.” It’s not marriage in the legal sense. It’s a separate status with its own rules.
The practical difference matters most at separation, where the rights of common-law partners are similar to married spouses in some areas (spousal support, parenting) and different in others (property division).
When You Become a Common-Law Spouse in Ontario
Under Ontario’s Family Law Act, you are common-law spouses if either:
• You have cohabited continuously for three years or more, or
• You are in a relationship of some permanence and have a child together (whether by birth or adoption)
“Continuously” doesn’t mean the relationship was perfect. Short interruptions (a few weeks apart, a temporary separation followed by reconciliation) usually don’t reset the clock. Longer interruptions might.
“Relationship of some permanence” with a child means more than a brief or casual relationship. The threshold is fact-specific.
This three-year threshold applies for spousal support and certain other purposes under the Family Law Act. The Income Tax Act uses a one-year threshold for tax purposes, which is why you might be considered common-law for taxes but not for spousal support. Different statutes, different definitions.
The Big Difference: Property Division
Here is where common-law separation differs most from a married separation, and it’s the difference that surprises people most often.
When married couples separate, Ontario’s Family Law Act requires them to equalize their net family property. Each spouse calculates the increase in their net worth from the date of marriage to the date of separation, and the spouse with the larger increase pays half the difference to the other. The matrimonial home gets special treatment. The system is designed to share the financial gains of the marriage equally.
None of this applies to common-law partners.
Common-law partners in Ontario have no automatic right to share in the property or wealth accumulated during the relationship. Each partner generally keeps what is in their own name. If the house is in one person’s name, it stays in that person’s name. If one partner contributed to a joint life but not to a jointly-titled asset, they don’t automatically get a share of that asset on separation.
This can produce results that feel deeply unfair, particularly for partners who supported the other’s career, raised children, or contributed financially to a home titled in the other partner’s name alone. The law does provide some remedies, but they are not automatic and they require proving specific things.
Remedies When Title Doesn’t Match Contribution
Where one partner contributed to an asset titled in the other’s name, Ontario recognizes a few claims that can produce some property recovery:
Resulting trust. Where you contributed money to the purchase of an asset titled in the other person’s name, with no intention of making a gift, a court can find that the other person holds part of the asset in trust for you.
Constructive trust based on unjust enrichment. Where one partner has been enriched at the other’s expense without a legal reason for the enrichment, a court can impose a trust over specific property to remedy the unfairness. Used most commonly where one partner contributed money or significant unpaid labour (renovations, business work, child care that freed the other to earn) and the other accumulated wealth.
Quantum meruit. A monetary award for the value of services provided.
These claims are not as predictable as the equalization regime that married couples enjoy. They depend on specific evidence, they’re heavily fact-driven, and they’re more expensive to pursue. The practical effect is that common-law partners often have less leverage in property negotiations than married spouses do.
This is one of several reasons that common-law couples benefit from clear written documentation during the relationship (a cohabitation agreement) and a thorough mediation process at separation if no agreement was made in advance.
The Matrimonial Home: Treated Differently for Common-Law Partners
For married couples, the Family Law Act gives both spouses equal rights to possession of the matrimonial home, regardless of whose name is on title. The home is treated specially in equalization, with the full value of the home counted against the title-holder rather than just the increase in value.
For common-law partners, there is no equivalent rule. The home belongs to whoever’s name is on title. If the house is in one partner’s name and the other partner has been paying half the mortgage for ten years, they have no automatic right to stay in the home after separation, and no automatic right to a share of the equity.
This is why title decisions matter for common-law couples. Who buys the house, whose name goes on title, how a deposit is documented, how mortgage payments are tracked, how renovations are paid for: these decisions during the relationship determine outcomes at separation.
In mediation, we work through the actual contributions each partner made, the documentation that exists, and what an outcome that recognizes both parties’ contributions looks like. Sometimes that’s straightforward. Sometimes it’s the hardest conversation in the file.
Spousal Support: Available to Common-Law Partners
In contrast to property division, spousal support is available to common-law partners in Ontario, on the same general framework as married spouses. Common law spousal support is governed by Ontario’s Family Law Act rather than the federal Divorce Act, but the test for entitlement and the amount calculation are essentially the same.
If you have cohabited for at least three years, or are in a relationship of some permanence with a child, you can claim spousal support after separation. The Spousal Support Advisory Guidelines apply, entitlement is assessed on the same grounds (compensatory, non-compensatory, contractual), and amounts and durations are calculated using the same formulas.
For more on how spousal support works in Ontario and how it gets negotiated in mediation, see our Spousal Support page.
Parenting and Child Support: Same as Married Couples
Where there are children, common-law parents face the same legal framework as married parents. The applicable statute is Ontario’s Children’s Law Reform Act rather than the federal Divorce Act, but the principles are essentially the same:
• Decisions about parenting time and decision-making responsibility are made based on the best interests of the child.
• Child support follows the Federal Child Support Guidelines.
• Parenting plans are built the same way and can be incorporated into a separation agreement.
For more on how parenting arrangements work, see our Parenting Plans and Parenting Schedules pages.
What a Common-Law Separation Agreement Covers
A common-law separation agreement is a written contract between the partners, signed by both, that records the terms of the separation. The framework is the same as a married separation agreement, just with different content where the law differs.
A typical common-law separation agreement addresses:
• Parenting arrangements, if there are children
• Child support, if applicable
• Spousal support, including whether it’s payable, how much, for how long
• Division of jointly held property
• Resolution of any trust or unjust enrichment claims relating to property in one partner’s name
• The matrimonial home or shared residence: who stays, who buys out, when it gets sold
• Joint debts, lines of credit, and bank accounts
• Joint accounts, insurance, benefits coverage
• Practical implementation issues like tax filings, dependent claims, and notice for future changes
Common-law separation agreements are recognized by Ontario law in the same way that married separation agreements are. Under Ontario’s Family Law Act, both are domestic contracts. When properly drafted, signed, and witnessed, both are enforceable as contracts. A well-drafted common law separation agreement protects both partners and gives the family a clear path forward.
Why Mediation Works Well for Common-Law Separation
Common-law separation often benefits from mediation more than married separation, for a few practical reasons:
The legal framework leaves more room to negotiate. Without an automatic equalization formula, common-law couples have wider latitude to design an outcome that reflects their actual contributions and intentions. That’s both a risk and an opportunity. In court, that latitude can produce unpredictable outcomes that don’t satisfy either party. In mediation, it produces tailored agreements that both parties can accept.
The factual and contribution questions matter more. In a married separation, the equalization math runs on numbers. In a common-law separation, it often runs on what each partner contributed, expected, and understood during the relationship. Mediation is a much better forum for that conversation than litigation.
The cost of litigation is harder to justify. Common-law property claims (unjust enrichment, constructive trust) are expensive to litigate, slow to resolve, and unpredictable. For most common-law couples, the assets at stake don’t justify the cost of a full trial. Mediation often produces a fair outcome for a fraction of the cost.
Children’s interests are clearer in mediation. Where there are children, the parenting conversation in mediation is centred on the kids rather than on adversarial positioning.
The Sage Harmony Process for Common-Law Separation
The process is essentially the same as for a married couple:
1. Separate phone intake. Each partner has a brief individual intake call with the mediator, usually 10 to 15 minutes, covering ground rules, fees, and basic background, with safety screening. Common-law separations often have specific issues (title disputes, undocumented contributions, complex blended family situations) that we’ll surface at intake.
2. Sign a mediation services contract. Once both partners have completed intake and are ready to proceed, we sign a contract for mediation services.
3. First joint mediation session and beyond. The duration of mediation depends on two things: the complexity of the issues being resolved and how agreeable the partners are with each other. Common-law mediations often need more time on property than married ones, because the legal default doesn’t do as much of the work, so common-law files can run longer than the average.
4. Drafting the separation agreement. We draft the agreement once the terms are settled, the same way we do for married couples. Sage Harmony is insured for separation agreement drafting.
5. Optional independent legal advice (ILA). Each party may choose to take the draft to their own family lawyer or common law lawyer for independent legal advice before signing. ILA is recommended but not required for a separation agreement to be legally binding in Ontario. We will explain the trade-off and respect your choice.
6. Signing. Each party signs the separation agreement in front of a witness. The agreement is binding.
If You Have a Cohabitation Agreement
Some common-law couples signed a cohabitation agreement before or during the relationship that addresses what happens on separation. If yours is one of them, the cohabitation agreement is the starting point for the separation conversation.
A properly executed cohabitation agreement is enforceable under Ontario’s Family Law Act the same way a separation agreement is. The mediation focuses on whatever the cohabitation agreement didn’t address, and on whether the agreement still reflects the parties’ circumstances.
If circumstances have changed significantly since the cohabitation agreement was signed, parties sometimes negotiate variations as part of the separation. The agreement can be amended or replaced in the separation agreement itself.
When Mediation Isn’t Right
Mediation usually isn’t appropriate when:
• One partner has been controlling the household finances and the other has limited financial knowledge or access. The power imbalance can make good-faith negotiation difficult.
• One partner is hiding income or assets. Mediation depends on accurate disclosure.
• There has been domestic violence or coercive control. Where one party isn’t safe to negotiate freely, mediation can recreate the dynamic.
• One partner refuses to engage in good faith.
• The property claim is complex and adversarial enough that formal disclosure tools (sworn statements, questioning, third-party records subpoenas) are needed.
If we see any of these dynamics, we’ll tell you and help you think through alternatives.
Cost
Mediating a common-law separation, including drafting the separation agreement and ILA for both parties, typically costs a small fraction of litigating the same issues. Most full mediated agreements come in at low thousands of dollars total. Contested common-law property claims, by contrast, regularly cost tens of thousands of dollars per side and take a year or more to resolve.
We charge by the session for mediation and provide an estimate during the intake process.
Frequently Asked Questions
Is there common law marriage in Ontario?
No. Ontario does not recognize common-law marriage as a form of legal marriage. There is a separate legal status called common-law spouse that triggers certain rights and obligations under provincial law, but it is not marriage and the rights are different in important ways (particularly for property).
How long do you have to live together to be common-law in Ontario?
For most purposes under Ontario’s Family Law Act, three years of continuous cohabitation, or a relationship of some permanence with a child. The threshold is different under the Income Tax Act (one year), which is why you may be common-law for tax purposes before you’re common-law for spousal support.
Do common-law partners split everything 50/50 when they separate?
No. Common-law partners in Ontario have no automatic right to share in property accumulated during the relationship. Each partner generally keeps what is in their own name. This is one of the biggest differences from a married separation.
Can I claim part of the house if it’s in my partner’s name?
Possibly, through claims like resulting trust, constructive trust, or unjust enrichment, if you contributed to the home in a way that justifies recognition. These claims are fact-specific and require evidence. They’re not automatic. Mediation is often the best forum to work through what your contribution was and what an outcome that recognizes it looks like.
Am I entitled to spousal support after a common-law separation?
Possibly. If you cohabited continuously for at least three years, or are in a relationship of some permanence with a child, you can claim spousal support on the same general framework as a married spouse. See our Spousal Support page for details.
Do common-law parents have the same parenting rights as married parents?
Yes. The legal framework for parenting (decision-making responsibility and parenting time) is essentially the same under Ontario’s Children’s Law Reform Act as it is under the federal Divorce Act for married parents. Best interests of the child applies the same way.
Can common-law partners have a separation agreement?
Yes. Common-law separation agreements are recognized as domestic contracts under Ontario’s Family Law Act, the same as married separation agreements. When properly drafted, signed, and witnessed, they are enforceable as contracts.
What if we never agreed about who owns what?
This is one of the situations where mediation is most useful. Without documentation, the legal answer is often unclear and litigation is unpredictable. Mediation lets the partners themselves work through what they each contributed, what their intentions were, and what a fair outcome looks like. The negotiated answer is usually better than what either party would get in court, and far less expensive to reach.
Does it matter that we called each other “husband” and “wife” or used joint surnames?
For legal purposes, no. Calling each other spouses, using a shared surname, filing taxes jointly, or being held out socially as married does not create a legal marriage in Ontario. It can be relevant evidence of cohabitation, but it doesn’t change your underlying legal status.
Start the Conversation
If you and your common-law partner are separating, we can help you negotiate a fair and durable agreement through mediation. Contact Sage Harmony to start the intake process.