Common Law Relationship in Ontario: Rights, Property, and Support

A common law relationship in Ontario is a conjugal partnership between two people who live together without being legally married. Ontario doesn’t use one single definition. For spousal support and estate support claims, you’re common law after three continuous years of cohabitation, or sooner if you have a child together and the relationship has some permanence. For federal tax purposes, the Canada Revenue Agency treats you as common law after just 12 continuous months. And even once you qualify, the rights that follow are narrower than what married spouses receive, particularly around property and inheritance.

When You Count as Common Law

The threshold depends on which law you’re looking at.

Under Part III of the Family Law Act, which governs spousal support, you’re a common law spouse once you and your partner have lived together continuously in a conjugal relationship for at least three years. A shorter period applies if you have a child together by birth or adoption and your relationship has “some permanence.”¹ The same definition carries over to dependant support claims against an estate under Part V of the Succession Law Reform Act.²

The CRA uses a much shorter clock. You’re common law for federal tax purposes after 12 continuous months of cohabitation in a conjugal relationship, and a separation of fewer than 90 days during that period doesn’t reset the count.³ You can owe tax obligations as a couple long before Ontario family law treats you as common law.

Whichever threshold applies, courts look for a relationship that functions like a marriage rather than a shared address. Shared shelter, financial support between partners, social recognition as a couple, and how you treat any children in the household all matter. No single factor is decisive.

Spousal Support After Separation

Common law partners who meet the Part III definition can claim spousal support on the same basis as married spouses.¹ Entitlement depends on financial circumstances, not a marriage certificate. Courts weigh each partner’s income, earning capacity, age, health, the length of the relationship, the roles each person played, and whether one partner sacrificed career opportunities for the household or the children.

Ontario courts routinely use the federal Spousal Support Advisory Guidelines to estimate the range and duration of payments once entitlement is established.⁴ The guidelines don’t decide whether you’re entitled in the first place.

Property Division

This is where the gap between common law and marriage is widest. Equalization of net family property under the Family Law Act applies only to married spouses; the Act defines “spouse” for property purposes as two people who are married to each other.¹ Common law partners are excluded.

When a common law relationship ends, property stays with whoever holds legal title. If your name isn’t on the deed, the account, or the investment, you don’t automatically get a share. That’s true no matter how long you lived together or what you contributed.

Unjust Enrichment

You aren’t left with nothing. Common law partners can bring an equitable claim for unjust enrichment by proving three elements: your partner gained something of value, you suffered a corresponding loss, and no contract, gift, or other legal reason justifies the imbalance. It’s the main legal tool for claiming property you don’t hold title to.

The Joint Family Venture

The Supreme Court of Canada’s 2011 decision in Kerr v. Baranow gave common law partners a more structured path. If you can prove unjust enrichment and also show your relationship operated as a “joint family venture,” a court can divide accumulated wealth proportionally instead of awarding a fixed dollar figure for specific contributions.

Courts look at four factors:

Mutual effort — both partners working toward shared goals, whether that meant pooling income, one partner handling domestic work so the other could build a career, or raising children together.
Economic integration — intertwined finances through joint accounts, shared expenses, or saving together for major purchases.
Actual intent — acting as though you intended to share your lives and assets, including referring to each other as spouses or naming each other in wills.
Priority of the family — sacrifices made for the family unit, like leaving a job to raise children or relocating for the other partner’s career.

There’s no presumption that every common law relationship qualifies. The person making the claim has to prove these factors on a balance of probabilities. When the evidence is there, the outcome can approach what married couples receive through equalization.

Time Limits

Timing matters. Property claims involving real estate carry a 10-year limitation period in Ontario. Purely monetary claims that don’t involve real property fall under the standard two-year limit. The clock starts at separation, so delay after a breakup can eliminate the claim entirely.

Inheritance if Your Partner Dies

Common law partners have no automatic right to inherit. The Succession Law Reform Act defines “spouse” for intestacy purposes by reference to section 1 of the Family Law Act, which covers only married spouses.² When someone dies without a will, the estate flows to their married spouse and children under a statutory formula. A surviving common law partner isn’t in the line of distribution at all, regardless of how long the relationship lasted.

A married spouse receives at least a preferential share of the estate. With no children, the married spouse takes everything. With children, the spouse takes the preferential share plus a fraction of the remainder.² A common law partner gets none of that.

Dependant Support Against the Estate

There’s one safety net. Under Part V of the Succession Law Reform Act, a common law partner can apply for support from the estate if the deceased was providing support or had a legal obligation to provide it immediately before death. The broader Family Law Act section 29 definition applies here, covering partners who cohabited at least three years or have a child together with a relationship of some permanence.²

Courts consider your financial needs, age, health, the standard of living you were accustomed to, the length of the relationship, and any contributions you made to the deceased’s property or welfare. You must file within six months of the Certificate of Appointment of Estate Trustee being issued. Late applications require the court’s permission and are harder to win.

If you want your common law partner to inherit reliably, a will is the way. Joint ownership of major assets like a home or bank account is the other common route, since jointly held property passes to the surviving owner outside the estate.

Taxes and Federal Benefits

Once the CRA treats you as common law, both financial lives change. You have to notify the CRA of the change by the end of the month following it, using Form RC65 or your online CRA account.³ Failing to report can trigger repayment demands for benefits you weren’t entitled to as a couple.

Two benefit programs commonly shift:

Canada Child Benefit payments are recalculated on combined adjusted family net income. If both partners were receiving separate payments, only one payment per family continues. The July 2025 to June 2026 payment period uses combined 2024 income.⁵ Continuing to collect separate payments after your status changes creates an overpayment that has to be repaid. Both partners must file annual returns to keep CCB flowing, even if one had no income.

The GST/HST credit is also recalculated on combined income. If the household total exceeds the eligibility threshold, the credit can disappear entirely.⁶ Couples who each received the full credit as single filers often see a sharp reduction after reporting the change.

Healthcare Decisions

If your common law partner becomes incapable of making their own medical decisions and hasn’t signed a Power of Attorney for Personal Care, Ontario’s Health Care Consent Act sets a ranked list of who can consent to treatment on their behalf. A spouse or partner sits at position four, after a court-appointed guardian, an attorney for personal care, and a Consent and Capacity Board representative.⁷ In practice, positions one through three are only filled if someone has taken formal legal steps, so the common law partner is usually the first person healthcare providers turn to.

The complication is family. A parent or adult child of the incapable person ranks at positions five and six. Disagreements can escalate to the Consent and Capacity Board. The straightforward fix is for both partners to sign a Power of Attorney for Personal Care naming each other, which moves your partner to position two and makes the authority explicit rather than something to be proven.

Cohabitation and Separation Agreements

A cohabitation agreement is a written contract between two people who live together or plan to, without being married. Under section 53 of the Family Law Act, these agreements can cover property ownership and division, support obligations, children’s education and moral training, and other matters relating to your affairs.¹ They cannot predetermine parenting time or decision-making responsibility, because courts retain the power to override those terms based on the child’s best interests.

Given that common law partners have no automatic property equalization, a cohabitation agreement is the closest thing to building those protections yourself. You can agree in advance on how to divide a home, savings, and other assets if the relationship ends. Without one, you’re left with unjust enrichment claims, which are expensive to litigate and uncertain in outcome.

What Makes It Enforceable

A cohabitation agreement can be set aside under section 56(4) of the Family Law Act if one partner failed to disclose significant assets, debts, or income, or if the other partner didn’t understand the nature or consequences of what they were signing.¹ Full financial disclosure is a legal requirement, not a courtesy. Both partners should disclose everything, real estate, business interests, pensions, investments, debts, and current values, and each should get independent legal advice before signing.

If You Later Marry

Under section 53(2) of the Family Law Act, a cohabitation agreement automatically becomes a marriage contract if you later marry.¹ The terms carry forward. If they no longer fit your circumstances, update the agreement before or shortly after the wedding.

Separation Agreements

Common law couples don’t need a divorce. No formal legal process is required to end the relationship itself. But if you share property, have children, or one partner needs support, a separation agreement under section 54 of the Family Law Act lets you settle those issues without going to court.¹ Unlike a cohabitation agreement, a separation agreement can address parenting time and decision-making responsibility, because by that stage the court can evaluate what’s actually in the child’s best interests.

Children’s Rights Don’t Depend on Marital Status

Children born to common law parents have the same legal rights as children born to married parents. Parenting time, decision-making responsibility, and child support are all determined on the child’s best interests, and Ontario’s child support guidelines apply equally.⁸ Your relationship status affects how you and your partner divide property and whether you owe each other support. It doesn’t affect what you owe your children.

Common Law vs. Marriage at a Glance

Many common law partners assume they have rights they don’t. The side-by-side:

Property on separation: Married spouses share the growth in net family property through equalization under section 5 of the Family Law Act. Common law partners keep whatever they hold title to and must pursue equitable claims for anything else.¹
Inheritance without a will: A married spouse inherits under the Succession Law Reform Act’s intestacy rules. A common law partner inherits nothing.²
Spousal support: Available to both, once the common law partner meets the three-year or child-based threshold.
Ending the relationship: Married couples need a divorce. Common law couples can simply separate.
Federal tax status: Both file as partnered after the CRA recognizes the relationship, with combined incomes for benefit calculations.

Marriage delivers automatic protections for property and inheritance. Common law status does not. If you want similar protections without marrying, you have to build them deliberately: cohabitation agreements, wills, joint ownership, and powers of attorney. Waiting until something goes wrong is the most expensive option.

1
Ontario.ca. Ontario Code R.S.O. 1990, c. F.3 – Family Law Act
2
Ontario.ca. Ontario Code R.S.O. 1990, c. S.26 – Succession Law Reform Act
3
Canada Revenue Agency. Marital Status
4
Department of Justice Canada. Spousal Support Advisory Guidelines
5
Canada Revenue Agency. Canada Child Benefit
6
Canada Revenue Agency. Who Is Eligible – GST/HST Credit
7
Ontario.ca. Ontario Code S.O. 1996, c. 2 – Health Care Consent Act, 1996
8
Government of Ontario. Parenting Time, Decision-making Responsibility and Contact