Canada has one of the highest common-law partnership rates in the developed world. Roughly 23% of Canadian couples live common-law. That is millions of people who assume prenups are only for marriage.
Here is the reality: common-law relationships can create serious legal and financial exposure, and the rules depend heavily on your province. In BC, many common-law partners are treated almost like married spouses after two years. In Ontario, property division works very differently, but you can still face claims around spousal support, unjust enrichment, and parenting and child support.
This guide explains when common-law partners in Canada should consider a "prenup" (usually a cohabitation agreement), what it can cover, where the risks are, and how to make it more likely to hold up if you ever separate.
Common-law prenup Canada: what you actually need (cohabitation agreement vs prenup)
In Canada, people often say "prenup" as shorthand for any relationship contract. Legally, the name usually depends on timing:
- Prenuptial agreement: signed before marriage
- Marriage contract: another common term (especially in Ontario)
- Cohabitation agreement: signed while you are living together but not married
If you are common-law and not planning a wedding soon, what you want is typically a cohabitation agreement. If you later marry, many provinces allow the cohabitation agreement to continue as, or be converted into, a marriage contract.
Do common-law partners have the same rights as married couples in Canada?
Sometimes, but not always. Canada does not have one single "common-law" rule. Your rights depend on your province or territory, how long you have lived together, whether you have a child together, and how your finances and property are structured.
Two areas matter most: property division (who keeps what) and support (spousal support and child support).
Property rights: the biggest place common-law couples get surprised
Many common-law partners assume either "we are basically married, so everything is 50-50" or the opposite: "we are not married, so we just keep what is in our own names." Both can be wrong depending on the province. The gap between expectation and legal reality is where the most expensive disputes happen.
Support rights: common-law partners can face spousal support claims
Even where property division rules differ for common-law partners, spousal support can still apply if you meet your province's definition of spouse or partner. A good agreement can set expectations around support, but support clauses are also one of the areas courts scrutinize most carefully, especially if the terms become clearly unfair over time.
Why a common-law prenup (cohabitation agreement) can be worth it
A well-prepared agreement is less about "planning for a breakup" and more about reducing uncertainty and legal costs. Common goals include:
- Protecting a home one partner bought before moving in together
- Keeping business ownership separate
- Clarifying what happens if one partner pays for renovations or the mortgage
- Protecting inheritances and family gifts
- Allocating responsibility for debts (student loans, business debt, tax debt)
- Setting expectations around spousal support
- Avoiding expensive litigation by writing down the deal while things are good
Without an agreement, you are relying on default provincial rules that may not match what either of you actually wants. And if you end up in court, you are paying lawyers to argue about things you could have settled over a kitchen table conversation.
Common-law prenup Canada: what it can cover (and what it cannot)
A cohabitation agreement can usually address most financial topics, but there are limits.
What a cohabitation agreement can usually cover
Property ownership and division. Who owns what today, what happens to property acquired during cohabitation, and how you treat increases in value (like a condo appreciating or an investment portfolio growing).
The home. Who stays, who buys out, timelines for sale, and how mortgage payments and renovations are treated. This is often the single most important clause for common-law couples.
Debts and liabilities. Who is responsible for which debts, and how joint credit cards or lines of credit are handled at separation.
Spousal support expectations. Whether support is waived, limited, or calculated by a formula, and how long support would last.
Business and professional assets. Ownership and growth of a corporation, partnership, or professional practice. What happens if family income is reinvested into the business.
Gifts and inheritances. How inheritances are treated if deposited into joint accounts or used toward the home.
What a cohabitation agreement generally cannot decide
Even with an agreement, some topics are limited or not enforceable:
- Child support: you generally cannot contract out of a child's right to support
- Parenting time and decision-making: you can write intentions, but courts decide based on the child's best interests at separation
- Anything that is unconscionable, signed under duress, or based on inadequate financial disclosure
Province-by-province: common-law rules (Ontario, BC, Alberta, Quebec)
If you take only one thing from this article, take this: common-law rights are provincial. The same couple can face very different outcomes depending on where they live.
British Columbia: common-law partners can be treated like married spouses after 2 years
BC is the province that catches the most common-law couples off guard.
Under the Family Law Act, once you qualify as "spouses" (often after living together in a marriage-like relationship for 2 years, or sooner if you have a child together), you can face a property division framework that looks a lot like marriage. That means increased risk that family property is divided and family debt is shared.
In practical terms: if you move in with a partner in BC and one of you owns a house, has significant investments, or runs a business, the clock starts ticking the day you begin living together. After two years, the default rules may treat those assets very differently than you expected. A cohabitation agreement signed early can define what stays separate and what is shared before those defaults kick in.
Ontario: no automatic property equalization, but that does not mean "no claims"
Ontario often works differently than people expect.
Common-law partners in Ontario generally do not automatically get the same property equalization regime as married spouses. But common-law partners can still face disputes about spousal support, ownership (what is in whose name, joint ownership, resulting trust), and claims like unjust enrichment if one partner contributed significantly to the other's assets.
Here is what that looks like in practice: if one partner pays $50,000 toward renovations on a home they do not own, or spends years supporting a partner's business without compensation, the courts may find that the contributing partner deserves something back, even without a marriage certificate. These claims are unpredictable, expensive to litigate, and a cohabitation agreement can address them up front.
Alberta: adult interdependent relationships create real rights
Alberta uses a distinct framework called adult interdependent relationships (AIR). You can become adult interdependent partners by living together for three or more years, by having a child together, or by signing an adult interdependent partner agreement.
Once you qualify, Alberta's family property laws can apply to your relationship. The Family Property Act and the Adult Interdependent Relationships Act together mean that common-law partners may face property division and support obligations that are similar in many ways to married spouses. This includes the division of property acquired during the relationship, pension interests, and potential spousal support obligations.
Because Alberta's regime can meaningfully affect property and support outcomes, Alberta common-law couples often benefit from a cohabitation agreement that clearly defines what each partner keeps, how shared property is handled, and what support expectations look like.
Quebec: de facto spouses and a fundamentally different legal system
Quebec operates under civil law rather than common law, which makes it genuinely different from every other province.
In Quebec, unmarried partners are called de facto spouses (conjoints de fait). Historically, de facto spouses have not had the same automatic rights as married spouses in several key areas, including property division and spousal support. The Supreme Court of Canada addressed this in the landmark Quebec v. A decision in 2013, and the Quebec government has been considering reforms, but as of 2026, de facto spouses still have fewer automatic protections than married couples in Quebec.
That does not mean "no risk." De facto spouses can still face claims related to unjust enrichment, joint ownership of specific assets, and obligations where one partner contributed to the other's enrichment. And if the law changes (reform has been discussed for years), couples without an agreement could be caught off guard.
A well-drafted contract under Quebec civil law (sometimes called a "convention de vie commune") can set clear expectations. Because Quebec law uses different terminology and frameworks, it is especially important to work with a Quebec family law notary or lawyer.
"We are common-law, but everything is in one person's name." Do we still need an agreement?
Potentially, yes. This is one of the most common situations where couples get into trouble.
Scenario one: one partner owns the home, the other contributes to mortgage payments, property taxes, or renovations. Even if legal title is in one name, disputes can arise about whether the other partner should be compensated for their contributions through claims like unjust enrichment or constructive trust.
Scenario two: one partner owns a business, the other contributes labour, unpaid work, or financial support that helps it grow. Over time, the non-owning partner may argue they helped build something they were never compensated for.
A cohabitation agreement can clarify whether payments are treated as rent versus building equity, whether renovation contributions create an interest in the property, and whether a partner will receive a buyout amount and how it is calculated. Getting this on paper while things are good is far cheaper than litigating it after a breakup.
Common-law prenup Canada: what to include (practical clause checklist)
Every couple's situation is different, but these are the clauses that commonly make the biggest difference.
1) Financial disclosure schedule
Most enforceability problems start with poor disclosure. Include schedules listing assets (home equity, savings, investments, pensions, business interests), debts (credit cards, student loans, CRA amounts owing, business liabilities), and income (employment income, dividends, commissions). This is not just a formality. Courts take missing or incomplete disclosure seriously, and it is one of the fastest ways to get an agreement thrown out.
2) The home and living expenses
Be specific about who owns the home now and how title is held, who pays what monthly, how you treat improvements and renovations, and what happens if you separate (sale, buyout, move-out timelines). Vague language like "we will figure it out fairly" does not hold up. The more specific you are, the better.
3) Property acquired during cohabitation
Clarify whether each partner keeps property in their own name, whether certain categories are shared, and how joint purchases (car, furniture, big-ticket items) are split. Many couples assume they are on the same page here and discover at separation that they are not.
4) Debts
Spell out who is responsible for pre-cohabitation debt, how joint debt will be paid, and what happens if one partner takes on new debt in their own name. This is especially important when there is a significant gap in debt levels between partners.
5) Spousal support framework
Support clauses are sensitive and one of the areas most likely to be reviewed by a court. Many couples use a clear waiver (where appropriate), a cap or time limit, or a formula tied to length of cohabitation. Because courts can override support clauses that become clearly unfair, this is a major reason Independent Legal Advice (ILA) matters. A lawyer can help you draft support terms that are firm but realistic enough to survive scrutiny.
6) Business protections
If one partner is an entrepreneur or professional, consider keeping shares and growth separate, clarifying whether family funds invested in the business create a claim, and setting a method for valuation if a buyout is ever needed.
Wondering what a solid draft looks like before you talk to a lawyer? Try Prenuply's guided questionnaire to generate a customized cohabitation agreement template based on your situation, your province, and your priorities.
Enforceability: what makes common-law agreements hold up better in Canada?
Courts look at fairness and process. You cannot control every outcome, but you can reduce risk significantly.
Key factors that tend to make agreements more enforceable:
- Independent Legal Advice (ILA) for both partners, not just one
- Full financial disclosure with documents to back it up (not just verbal estimates)
- No pressure or last-minute signing (give yourselves weeks, not days)
- Clear, plain language that matches what the couple actually does
- The agreement is not grossly unfair at the time of signing or enforcement
The single biggest mistake couples make is skipping ILA or rushing the process. An agreement that took two months to prepare and was reviewed by two lawyers is far harder to challenge than one signed the week before moving in together.
When should common-law partners sign a cohabitation agreement?
The best time is usually before moving in together, or as early as possible after. The longer you wait, the more tangled your finances become, and the harder it is to draw clear lines.
Practical timing tips:
- Start the conversation weeks or months before cohabitation, not the week you are signing a lease
- Gather documents early (bank statements, mortgage info, investment summaries)
- Leave enough time for both partners to get ILA without feeling rushed
- If you have already been living together for years, it is not too late. Many couples sign agreements years into cohabitation, especially after buying a home, starting a business, or having children
How to bring up a prenup with a common-law partner
Common-law couples often avoid this conversation because they do not see themselves as "formal," they worry it signals a lack of trust, or they are not sure what the law actually says. The irony is that common-law couples often have less legal clarity than married couples, which makes the conversation more important, not less.
Ways to frame it constructively:
- As a household planning document, like insurance or a will
- As a way to protect both partners from uncertainty and expensive legal disputes
- As a way to keep money conflict from poisoning the relationship later
Try language like:
- "I want us to be clear and fair about money before we combine everything."
- "If we ever separated, I would rather follow a plan we chose than leave it to default rules we did not pick."
- "I want both of us to get legal advice so it feels balanced."
The key is framing it as something you are doing together, not something one partner is imposing on the other. If your partner resists, that is normal. Give them time and space to process, and suggest they talk to their own lawyer independently.
Costs: is a common-law prenup cheaper than dealing with a breakup dispute?
Almost always, yes. The cost of a cohabitation agreement varies based on complexity, province, and how much negotiation is involved. Typical cost drivers include business ownership and valuations, multiple properties, support clauses and income complexity, and prior relationships with children.
But here is the comparison that matters: a cohabitation agreement typically costs a fraction of what a contested separation costs. Family law litigation in Canada can easily run into tens of thousands of dollars or more. An agreement that costs a few thousand dollars up front can save you from a six-figure legal fight later.
Common-law prenup Canada: realistic scenarios
These examples show why common-law couples often benefit from getting things in writing.
BC couple moves in, one partner owns a condo
Partner A owns a condo with $250,000 in equity. Partner B moves in and helps pay monthly expenses. In BC, after two years of living together in a marriage-like relationship, the condo and its growth may be treated under BC's family property rules. Without an agreement, Partner A could face a claim to share property they bought and paid for before the relationship even started. A cohabitation agreement can define whether the condo and its appreciation stays separate, and whether Partner B receives compensation for specific contributions like mortgage payments.
Ontario couple, one partner pays for major renovations
Partner A owns a house. Partner B pays $40,000 toward a basement renovation and also contributes to monthly bills. Ontario does not automatically equalize property for common-law partners, but Partner B may have a strong claim for compensation through unjust enrichment or constructive trust. A cohabitation agreement can define up front whether that $40,000 is a gift, rent, a loan, or creates a repayment obligation. Without that clarity, you are looking at a courtroom argument about what both of you "intended" years earlier.
Alberta couple, one partner has significant student debt
Partner A has $70,000 in student debt. Partner B has savings and they want to buy a home together. Without an agreement, there is uncertainty about whether joint assets could be affected by one partner's pre-existing debt, and about what happens to joint home equity if they separate. A cohabitation agreement can keep the debt firmly with the partner who incurred it and set clear rules for how the home equity is divided.
Next steps: create a clear starting point, then get legal advice
If you are common-law and moving in together, buying property, mixing finances, or simply want clarity about where you stand, a cohabitation agreement is one of the most practical things you can do for your relationship and your financial future.
You do not need to walk into a lawyer's office with nothing. Prenuply helps you generate a customized cohabitation agreement template by answering guided questions about your situation, your province, and your priorities. You get a well-organized draft that you can take to your lawyers for review, which saves time and money on both sides.
Legal disclaimer
This article provides general information about prenups for common-law partners in Canada. It is not legal advice. Prenuply AI Inc. is not a law firm and does not provide legal services or legal advice. Prenuply AI Inc. is a technology company, not a legal services provider. You should always consult a qualified family lawyer in your province, and Independent Legal Advice (ILA) is essential for enforceable prenups and cohabitation agreements in Canada.