What is a cohabitation agreement?
A cohabitation agreement is a written contract between partners who live together, or plan to, without being married. It sets out who owns what, how property is shared if you separate, and whether either of you will pay support. It matters because Ontario's property-sharing rules for married couples do not apply to common-law partners.
Key points
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Unmarried partners have no automatic right to share property on separation. Claims depend on whose name is on title, and on court-made rules such as unjust enrichment.
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A partner can claim spousal support after three years of living together. They can claim sooner if they live together in a lasting relationship and are parents of a child together.
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A cohabitation agreement can cover property, debts, support and the home, but not future parenting arrangements.
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It must be in writing, signed by both partners and witnessed. It holds up best with full financial disclosure and a lawyer for each partner.
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If you later marry each other, it automatically becomes a marriage contract.
Moving in together? Book a free 15-minute call about a cohabitation agreement.
Why do common-law couples sign cohabitation agreements?
Ontario law treats unmarried partners very differently from married spouses, and many people only find out when they separate. Without an agreement:
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Property. Married spouses share the growth in their net worth through equalization under the Family Law Act. Common-law partners have no automatic sharing. Each keeps what is in their name, unless a court finds unjust enrichment or a joint family venture (Kerr v. Baranow, 2011 SCC 10).
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The family home. Married spouses have an equal right to live in the matrimonial home, whoever owns it. A common-law partner who owns the home can generally require the other to leave.
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Spousal support. Common-law partners can claim it after living together continuously for at least three years. They also can claim sooner if they lived together in a relationship of some permanence and are the parents of a child together.
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Children. Child support and parenting follow the same rules for all parents, married or not.
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Death without a will. A married spouse inherits a share. A common-law partner does not, though they may be able to claim support from the estate.
Take a partner who helped pay for a home in the other's name, or gave up income to raise children. Without an agreement, they may have to go to court and prove a claim based on fairness. That is slower, more expensive and less predictable than a claim under a statute. Strict deadlines also apply: generally two years for a claim to money, and ten years only for a claim to a share of land (McConnell v. Huxtable, 2014 ONCA 86).
A partner who owns most of the property faces the opposite risk: a claim they did not see coming. A cohabitation agreement replaces that uncertainty with terms you chose. See Common-law relationships in Ontario.
What can a cohabitation agreement cover?
Partners who live together, or intend to, and are not married to each other can make a cohabitation agreement. It can set their rights while living together, on separation and on death. A typical agreement deals with:
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The home. Who owns it, how a down payment from one partner is credited, who pays the mortgage, and what happens to the home and its growth in value if you separate. This is often the main reason couples sign one, especially when one partner already owns the home or a parent helped with the purchase.
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Other property and debts. What stays separate, what is shared, and how joint accounts and debts are divided.
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Spousal support. Whether either partner will pay support on separation, and if so how much and for how long, or a waiver. A court can still set aside a support term that leaves a partner in unconscionable circumstances or on public assistance.
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Claims based on fairness. A release of unjust enrichment and similar claims, so that contributions are dealt with only as the agreement says.
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Death. How the agreement fits with each partner's will, insurance and pension beneficiaries.
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The children's upbringing. Education and moral training of the childre can be addressed in the agreement, subject to the children's best interests.
Cohabitation agreement cannot cover decision-making responsibility or parenting time in advance. Those are decided at separation, in the children's best interests. A court can also disregard child support terms that are unreasonable compared with the Child Support Guidelines.
Will a cohabitation agreement hold up?
The same rules apply as for marriage contracts. The agreement must be in writing, signed by both partners and witnessed. A court can set it aside, in whole or in part, in limited cases. Some examples include a partner not disclosing significant assets or debts, not understanding the agreement, or signing under duress.
See Marriage contracts in Ontario.
To make your cohabitation agreement last:
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Exchange written financial disclosure before signing, with values and other supporting documents, and attach it to the agreement.
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Each partner should have their own lawyer and get independent legal advice. See Independent legal advice in Ontario family law.
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Do not sign on moving day. Pressure to sign right before a move or a home purchase closing is exactly what a later challenge points to.
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Keep to it. If you put separate money into the shared home, the agreement should say how that is treated.
What happens if we marry or have children?
If you marry each other, the cohabitation agreement automatically becomes a marriage contract. That is convenient, but the terms were written for an unmarried couple. Once married, you gain rights the agreement may not mention, such as equalization of net family property and an equal right to live in the matrimonial home. Review the agreement with a lawyer before the wedding, and update it if needed.
If you have a child, two things change. Support obligations between you may arise sooner. A spousal support waiver signed before children were born is also more open to challenge, because the circumstances it was based on have changed. Child support is always owed under the Guidelines, whatever the agreement says. Many couples add a review clause triggered by the birth of a child or a move to part-time work.
If you buy a home together, check whether the agreement still reflects how you are paying for it and how title is held.
Talk to a family lawyer about a cohabitation agreement
Start with a free 15-minute call to talk through your situation and the next step. From there, we can draft your agreement, or advise you on one your partner's lawyer prepared.
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A free 15-minute phone call to talk through your situation and the next step
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Cohabitation Agreement from $1,299 plus HST
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Independent Legal Advice on an agreement your partner's lawyer prepared: $699 plus HST
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Later meetings by phone, by video or in person at 5200 Yonge Street, Suite 200, North York
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Urgent or out-of-hours: leave a voicemail or send a text to 416-858-1320
Book a free 15-minute call about your cohabitation agreement · Call 416-858-1320
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Last reviewed: November 1, 2026
This page is general information about Ontario and federal law, not legal advice. Reading it or contacting us does not create a lawyer-client relationship. Laws and court fees change; check the date above.