Common-law separation in Ontario — what's different from marriage

TL;DR — In Ontario, a common-law separation is not a smaller version of a divorce. Child support works exactly the same, and spousal support can still apply after three years together or once you have a child. But there is no automatic property split. You each keep what is in your own name, and the only way your partner reaches an asset titled to you is by proving in court that they helped pay for it. That one difference shapes almost every decision you make next.

Most men in a common-law relationship assume the law treats them like a married couple after a few years together. It does for some things and does not for the one that usually matters most — the house, the savings, the pension. Knowing which rules apply to you is the difference between a clean separation and a fight over money that never had to happen.

Are you actually common-law under Ontario law?

Ontario does not have a single definition of common-law — it has one for support and a different practical reality for property. Under the Family Law Act, you are a common-law "spouse" for support purposes in one of two ways. The first is living together continuously for at least three years. The second is living together in a relationship of some permanence and having a child together. The three-year clock counts continuous cohabitation, so a short break can reset it, and the province's own guidance on dividing property when a relationship ends confirms the split treatment.

The word "spouse" here is misleading. Meeting the three-year mark makes you a spouse for support — it does not make you a spouse for property. That distinction is the whole subject of this article, and it catches men off guard because they have heard for years that "after three years you're basically married." For support, close to true. For the house and the savings, not at all.

Three years of continuous cohabitation makes you a common-law spouse for support in Ontario

There is a second trap in the word "continuous." A relationship that stops and restarts can reset the clock, and the exact date you separated matters for both the three-year count and any support claim. If your timeline is messy, write down the dates you lived together and apart while you still remember them clearly, because you may have to prove them later.

What stays exactly the same as a married separation?

Two things do not change based on whether you were married. The first is child support. It follows the child, not the relationship, so it is calculated the same way for every parent in Ontario — from the payor's gross income and the number of children, using the Federal Child Support Guidelines. If you want the actual number rather than the theory, our guide on how child support is calculated in Ontario walks through the tables.

The second is spousal support entitlement. A common-law partner who meets the three-year or child-together test can claim spousal support under Part III of the Family Law Act, using the same Spousal Support Advisory Guidelines a married spouse would. The difference is that the length of your cohabitation replaces the length of a marriage in the math. Entitlement is never automatic — the person asking has to show a real economic need or a disadvantage that came out of the relationship, which we cover in common-law spousal support in Ontario.

How much spousal support, and for how long?

If support does apply, the amount and duration come from the Spousal Support Advisory Guidelines — the SSAG, an informal but widely followed formula that Ontario courts use as a starting point. For a common-law relationship, the years you lived together stand in for the years of a marriage. The longer you were together and the wider the income gap, the higher and longer support tends to run.

As a rough guide, a relationship without children points to somewhere between half a year and a full year of support for every year you lived together. Two thresholds change the picture. Support can become indefinite once you have lived together 20 years or more. It can also run long under the "rule of 65" — when your years together plus the recipient's age at separation add up to 65 or more. That is why a 15-year common-law relationship is treated very differently from a four-year one. To see the numbers for your own income, the free calculator runs the support range in about two minutes.

Why don't common-law partners split property the same way?

This is the difference that matters. When married spouses separate in Ontario, the law runs an equalization — the equalization payment, which is the cash transfer that evens out the growth in each person's net worth during the marriage. Common-law partners get none of that. There is no equalization, no automatic half of the house, and no special protection for the home you shared.

In practice, that means each of you walks away with what is in your own name. The car titled to you stays yours. The savings account in her name stays hers. The house belongs to whoever is on title. If only one name is on it, the other has no automatic right to a share of its value — or even a guaranteed right to stay in it. This is the mirror image of the equalization and property division rules for married couples, and the gap between the two is exactly why people wrongly assume they are protected.

Jointly owned things are the exception, and they cut both ways. A home, account, or vehicle in both names is presumed to be owned equally, so it gets divided or sold and split regardless of who paid more. The same logic applies to joint debts — a line of credit or credit card in both names stays both your responsibility to the lender, and no separation agreement can change what the bank is owed. Sort out the joint items first, because they are the assets and debts you can settle without a lawyer arguing about contribution.

Can your ex still claim a share of what's in your name?

Yes, and this is where men get complacent. "It's in my name" is a strong starting position, not a guarantee. A common-law partner can ask a court for a share of a specific asset through a trust claim. The argument is that even though the asset sits in your name, they helped pay for it — and keeping the whole thing would be unfair to them.

The main route is unjust enrichment, which the Supreme Court of Canada set out in Kerr v Baranow (2011 SCC 10). Your partner has to prove three things: that you were enriched, that they suffered a matching loss, and that there was no legal reason for it, such as a gift or a contract. Where the couple ran their lives as a genuine team, a court can treat it as a joint family venture and award a share of the wealth that was built. So the man who kept the house in his name while his partner paid every grocery bill and raised the kids is not as protected as he thinks. Documentation of who paid for what becomes the entire case.

A short example shows how real this is. A man owns the home in his name and pays the mortgage from his salary. His partner covers the household bills, buys the groceries, and raises their children for ten years without outside work. If they separate, she has no automatic claim to the house — but she has a strong unjust enrichment argument that her unpaid work let him build that equity. That is exactly the joint family venture a court can reward, and the man who assumed "my name, my house" is suddenly negotiating a share.

The common-law myths that get men into trouble

Three beliefs cause most of the damage. The first is "after three years we're married in the eyes of the law" — true for support, false for property. The second is "the house is mine because it's in my name, so I have nothing to worry about" — true until a trust claim lands, then it is a live fight. The third is the opposite error — "she's owed half of everything" — which leads men to hand over far more than the law requires out of guilt or fear.

A fourth myth is quieter and just as costly — "we had a verbal deal, so I'm covered." A conversation about who gets what carries almost no weight when money is on the line and memories diverge. What protects you is a signed, written agreement, not a handshake you both remember differently a year later.

The reality sits between the myths. You are exposed on support and on any asset you built together, and protected on assets that are clearly and only yours. The single document that removes the guesswork is a cohabitation agreement — a contract signed while you are still together that decides in advance who owns what and whether support will be paid. If you are still in the relationship, or reconciling, read what a cohabitation agreement does and when to sign one before anything else.

The one thing to do this week

Write down every asset over a few thousand dollars — the home, vehicles, savings, investments, pensions — and beside each one note two things: whose name it is in, and who actually paid for it. That single list tells you where you are genuinely protected and where a trust claim could reach, and it is the first thing any advisor will ask for. You cannot make a good decision about a common-law separation until you can see, on one page, what is clearly yours and what is arguable.

Where Cairn helps next

A five-minute intake gives you a specific Ontario plan, your support numbers, and the one thing to do this week. Free, no credit card.

• Your specific Ontario plan, free, in five minutes
• The action plan that tells you the next step every week
• Built only for Ontario family law

See your 5-minute plan →