Key Takeaways
- Since 2020, qualifying common-law partners divide property under the same legislation as married spouses. Moving in together now has default financial consequences, and a cohabitation agreement is how couples set their own terms instead.
- A cohabitation agreement can define what stays separate, what becomes shared, and how support would work if the relationship ends, and it can be written to continue applying if you later marry.
- It is not the same as an adult interdependent partner agreement, which creates partner status rather than setting financial terms. The two are routinely confused.
- Enforceability follows the familiar rules: full disclosure, voluntary signing, independent legal advice, and the statutory acknowledgments for property provisions.
Couples used to treat moving in together as the low-stakes alternative to marriage. In Alberta, that stopped being legally true in 2020, when family property legislation was extended to adult interdependent partners. Live together long enough, three years, or less with a child, and the default rules of property division and partner support apply to you, whether you thought about them or not. A cohabitation agreement is the tool for couples who would rather choose their terms than inherit them. Here is what it does, who actually needs one, and what makes it stick.
What the Default Rules Do Without One
Once you qualify as adult interdependent partners, the Family Property Act presumes property built during the relationship is divided equally at the end, and Alberta's Family Law Act makes partner support available. Exempt property, what you brought in, gifts from third parties, inheritances, keeps its protection only where it can be traced, and growth on exempt property can still be divided. Our guides to common-law property rights and when you become common law cover the defaults in detail. A cohabitation agreement replaces those defaults with terms the two of you actually chose.
What a Cohabitation Agreement Covers
- Property in and property out. What each of you brings to the relationship, documented up front so tracing is never the problem, and what happens to it if you separate.
- The home. Whether one partner's house stays theirs, how contributions to the mortgage or renovations are treated, and what happens to a jointly purchased home.
- Businesses and professional practices. Ring-fencing a company, its growth, and its income from division, which for business owners is usually the single biggest reason to sign.
- Debts. Whose liabilities stay whose.
- Support. Whether partner support would be paid on separation, on what terms, or a waiver, drafted carefully, because support waivers get the closest scrutiny.
- The marriage question. A well-drafted agreement states whether it continues to apply if you marry, effectively converting into a prenuptial agreement, so the wedding does not silently reset your legal position.
Child support cannot be bargained away in advance: it belongs to the child, and no agreement overrides the guidelines. Parenting of future children likewise cannot be pre-decided.
Not the Same as an Adult Interdependent Partner Agreement
The similar names cause real confusion. An adult interdependent partner agreement is a creature of the Adult Interdependent Relationships Act: signing one makes you partners immediately, with all the default rights that status carries. A cohabitation agreement does roughly the opposite job: it does not change your status, it sets the financial terms that will apply however your status evolves. Couples who want the status use the first. Couples who want to customize the consequences use the second. Some sophisticated arrangements use both deliberately, which is exactly the kind of thing to do with advice rather than by accident.
Who Should Seriously Consider One
Not every couple needs this document. The cases where it earns its fee:
- One partner owns a home the couple will live in.
- One partner owns a business or professional practice, where division or valuation fights would be existential.
- Significant asset or income disparity, or one partner arriving with substantial investments or pension value.
- Expected inheritances or family gifts, especially where family money will flow into shared assets.
- Second relationships and blended families, where protecting children's inheritances from a prior relationship matters.
- Partners who watched a previous separation burn money and want the next chapter pre-agreed.
What Makes It Enforceable
The rules are the same ones that govern every family agreement in Alberta, and they are covered at length in our guides to separation agreements and independent legal advice: full and honest financial disclosure from both sides, genuinely voluntary signing without a moving-truck ultimatum, independent legal advice for each partner, and the Family Property Act acknowledgment certificates for the property provisions. Timing deserves its own mention: the worst moment to negotiate a cohabitation agreement is the week one partner's lease ends. Start months ahead, so nobody signs under logistical pressure, and the agreement's voluntariness is beyond argument.
Agreements should also be revisited at life milestones: marriage, children, a business sale, a major purchase. A document that reflected your lives at twenty-eight may fit badly at forty, and an update negotiated calmly costs a fraction of a challenge litigated bitterly.
Frequently Asked Questions
Are cohabitation agreements enforceable in Alberta?
Yes, when made properly: full financial disclosure, voluntary signing, independent legal advice for each partner, and the statutory acknowledgments for property provisions. Missing pieces are what get agreements set aside.
Do we need one before moving in together?
Before is ideal but not required. A cohabitation agreement can be signed at any point in the relationship, and signing one at year two still beats litigating the defaults at year ten.
What happens to the agreement if we get married?
Whatever the agreement says. A well-drafted one states expressly whether it survives marriage, functioning as a prenuptial agreement from the wedding onward. Silence on the point creates avoidable argument.
Can a cohabitation agreement waive child support?
No. Child support belongs to the child and follows the guidelines regardless of what parents agreed in advance. Property and partner support are the proper subjects of the agreement.
Is a cohabitation agreement the same as an adult interdependent partner agreement?
No. An adult interdependent partner agreement creates partner status immediately. A cohabitation agreement sets the financial terms of the relationship without changing status. The two do different jobs.
Choose Your Terms
A cohabitation agreement is financial architecture: property, business interests, disclosure, and tax treatment, drafted to hold. That is precisely the work William Aadil Musani built this practice around, after years in corporate law, tax law, and mergers and acquisitions. See our domestic agreements page, or book a confidential consultation or call (403) 804-0497.
This article is general information about Alberta family law and is not legal advice. Reading it does not create a solicitor-client relationship. Every situation is different, and you should speak with a lawyer about your specific circumstances.
William Aadil Musani is a Calgary family lawyer and the founder of Cunningham Family Law. Before family law, he practiced corporate law, tax law, and M&A with international firms and a Tier-1 Canadian tax boutique, experience he now applies to financially complex divorce and separation matters. More about William →