In Ontario, common-law relationships have become increasingly common. Many couples choose to live together without marrying, believing that cohabitation provides similar legal protections as marriage.
While this belief is widespread, it is also deeply flawed.
Under statutes such as the Family Law Act and the Children’s Law Reform Act, there are significant legal differences between married spouses and common-law partners. Below, we will explore this area in more detail. We will also address why it is important to establish a cohabitation agreement with your common-law partner.
The Common Misunderstanding: “We Live Together, So We Are Essentially Married”
The term “common-law marriage” is often used to describe a long-term romantic relationship where the couple resides together but has never legally married.
While this terminology may be convenient, it has no legal standing in Ontario. The province does not recognize common-law marriage as equivalent to a legal marriage. This becomes especially clear when it comes to the division of property.
Under Ontario law, married spouses have the right to family property upon separation. This means that each spouse is generally entitled to share in the increase in value of the property accumulated during the marriage (regardless of whose name is on the title).
However, this property-sharing does not apply to common-law couples.
Common-law partners do not have an automatic right to property division or equalization. Unless the property is jointly owned or there is a trust claim (such as a constructive trust or resulting trust), each partner retains what they brought into the relationship or acquired in their name during the relationship.
This can lead to harsh or unfair outcomes. Especially when one partner has made significant contributions to a home that is legally owned by the other.
What Is a Cohabitation Agreement?
A cohabitation agreement is a legal contract between two individuals who are living together or intend to live together in a conjugal relationship.

This agreement provides a contractual method for common-law partners to protect themselves by allowing partners to define their rights and responsibilities during the relationship. It also establishes how matters will be handled should the relationship break down.
A contract of this nature clearly lays out:
- Who owns what property and assets
- Who is responsible for certain financial obligations
- How assets (or debts) will be handled if the relationship ends
- Provisions related to spousal support (although these must comply with applicable laws and be fair and reasonable at the time of enforcement).
It is important to note that this agreement can be created before or during the cohabitation period.
Why You Should Consider a Cohabitation Agreement
1. Protecting Property Rights
Without a cohabitation agreement, any property solely owned by one partner will generally remain theirs. This will be the case even if the other partner contributed to mortgage payments, renovations, or maintenance. A cohabitation agreement can override this default rule if it meets all legal criteria.
2. Reducing Legal Conflict
Breakups can be emotionally and financially challenging. A clear agreement reduces the risk of disputes and litigation. If matters are already settled in writing, there is less room for disagreement during an already stressful time.
3. Clarifying Financial Expectations
Cohabitation agreements can outline how shared expenses are to be handled. This includes how each partner will contribute to the other's assets and how debts will be managed. This transparency helps avoid resentment or misunderstandings.
4. Providing Certainty and Security
Clarity around ownership and obligations creates peace of mind for everyone. Especially in situations where one or both partners are bringing significant assets into the relationship. It is also very important for these certainties to be established when children from a prior relationship are involved.
5. Supporting Estate Planning Goals
Although this is not the main purpose of a cohabitation agreement, it can complement other estate planning tools. For example, it can address what happens to jointly owned property upon death. However, it is important to make sure that wills and beneficiary designations are also updated.
What Makes a Cohabitation Agreement Valid?
To ensure a cohabitation agreement is legally enforceable in Ontario, it must meet certain requirements:
1. It Must Be in Writing and Signed by Both Parties
Verbal agreements do not carry legal weight in this context. The agreement must be formalized in writing and signed by both partners in the presence of a witness.
2. Full Financial Disclosure
Each partner must disclose their financial situation honestly and thoroughly. This includes income, assets, debts, and other relevant financial details. Failure to disclose this information could lead to the agreement being set aside by the court.
3. Independent Legal Advice
Both parties should obtain legal advice from separate lawyers. This step ensures that each partner understands their rights and the implications of the agreement. It also helps prevent future claims of coercion or unfairness.
4. Fairness at the Time of Signing and Enforcement
An agreement that is grossly unfair or one-sided may not hold up in court. Judges have the discretion to invalidate or modify an agreement if it is found to be biased. This also stands if there was undue pressure on the signee when it was signed.
Recent Legal Developments
In recent years, judges have emphasized the importance of respecting parties’ autonomy when they have clearly laid out their intentions in writing and followed appropriate procedures.
That said, courts also maintain a degree of discretion.
Agreements may still be challenged and examined in light of changing circumstances or evolving legal standards. This is most notable when they involve spousal support or what is deemed to be an unfair outcome.
This underscores the importance of drafting the agreement carefully and reviewing it periodically when major life changes occur.
Planning Ahead Is Not Just for Married Couples. Connect With Us for Expert Guidance
In Ontario, living together does not provide the same legal protections as marriage. Relying on the assumption that a long-term relationship will guarantee certain rights can leave individuals vulnerable. Especially in cases involving property ownership or financial dependency.
At Howard Nightingale Professional Corporation, we provide legal support tailored to your specific relationship and financial goals.
Schedule a confidential consult with our family law team to explore whether a cohabitation agreement is right for you.

Your information will always remain private and confidential.