Key Takeaways
- There is no six-month rule. In Alberta family law you generally become an adult interdependent partner after three continuous years of living in a relationship of interdependence.
- The three years can shorten: a child together plus a relationship of some permanence, or a signed adult interdependent partner agreement, each create the status earlier.
- The federal tax definition of common law (twelve months, for CRA purposes) is a different test for a different purpose. Meeting one does not mean you meet the other.
- The status matters: it opens property division, partner support, and estate rights, and it starts deadlines that can expire two years after the relationship ends.
"Are we common law?" sounds like a yes-or-no question, and in Alberta it has a precise legal answer that surprises most people who ask it. Some believe six months of cohabitation does it. Others assume nothing short of marriage changes their legal position. The real rules sit in Alberta's Adult Interdependent Relationships Act, and because the status now carries property rights, support rights, and hard deadlines, getting the answer right matters. Here is how the test actually works.
The Legal Test: Adult Interdependent Partner
Alberta legislation does not use the term common-law spouse. The status is adult interdependent partner, and there are three ways to acquire it:
- Three years of living together. You have lived with the other person in a relationship of interdependence for a continuous period of at least three years.
- A child, plus some permanence. You live together in a relationship of interdependence of some permanence and have a child together by birth or adoption. The three-year clock does not apply in this stream.
- A written agreement. You and the other person sign an adult interdependent partner agreement in the prescribed form. The status begins with the agreement rather than the calendar. A person who is still married cannot enter into one of these agreements, and relatives can become partners only through this route.
What "Relationship of Interdependence" Means
Time alone is not enough. A relationship of interdependence is one where you share one another's lives, are emotionally committed to one another, and function as an economic and domestic unit. The legislation looks at factors such as whether the relationship is exclusive, how household decisions and chores are shared, how finances are arranged, whether you present as a couple, and whether children are part of the picture. Roommates who split rent for four years do not qualify. A committed couple who keep separate bank accounts might. It is the overall picture that decides, which is exactly why borderline cases end up argued.
The Six-Month Myth, and Where Twelve Months Comes From
The six-month figure has no basis in Alberta family law. The twelve-month figure people half-remember is real but belongs to a different system: the Canada Revenue Agency treats you as common-law partners for tax purposes after twelve months of conjugal cohabitation, or sooner where you live together and have a child together, which affects tax returns and benefits. It has no effect on property division or partner support in Alberta. It is entirely possible to be common law for CRA purposes and not an adult interdependent partner, and for a while, vice versa.
What the Status Changes
Becoming an adult interdependent partner is not a formality. It changes your legal position in several ways:
- Property. Since 2020, adult interdependent partners divide family property under the Family Property Act, the same legislation that governs married spouses. Our guide to common-law property and support rights covers what that means in practice.
- Support. A partner can seek partner support under the Family Law Act if the relationship ends.
- Estates. A surviving partner has inheritance rights if the other dies without a will, and family maintenance claims are available.
- Deadlines. Property claims generally must be started within two years of when you knew or ought to have known the relationship had ended, and support claims should be raised promptly as well, since limitation arguments can arise. The rights come with a clock.
How the Status Ends
Adult interdependent partnership does not end just because things cool off. In general terms, it ends when the partners live separate and apart for more than one year with the intention that the relationship is over, when they sign a written agreement recording that it has ended, when one of them marries someone else or enters an adult interdependent partner agreement with someone else, or in other defined circumstances, including a declaration of irreconcilability under the Family Law Act. The end date matters because the two-year limitation periods run from it, which is why identifying it precisely is one of the first things we do on a common-law file. If you are unsure where you stand, our common-law separation page outlines the process from here.
If You Do Not Want the Status
Couples who want to live together without the default property and support consequences can sign a cohabitation agreement setting their own terms. That is a deliberate, documented choice, with financial disclosure and independent legal advice, rather than an assumption that the law will not apply to you. Assuming has a poor track record.
Frequently Asked Questions
Is it six months or three years to be common law in Alberta?
Three continuous years of living in a relationship of interdependence, for Alberta family law purposes. The six-month figure is a myth, and the twelve-month figure is the federal tax definition, which is a separate test.
Do we need to register anything to become common law?
No. The status arises automatically from the way you live. The only paperwork route is a signed adult interdependent partner agreement, which creates the status immediately.
Does having a child together make us common law right away?
Having a child together shortens the timeline: partners with a child qualify once the relationship has some permanence, without waiting three years. The relationship still has to be one of genuine interdependence.
Can a married person have an adult interdependent partner?
A married person cannot sign an adult interdependent partner agreement. Whether someone still married to a third person can otherwise acquire the status is a technical question, and anyone in that situation should get specific advice.
When does adult interdependent partnership end?
Generally after one year of living separate and apart with the intention the relationship is over, on a written agreement that it has ended, or when one partner marries someone else, among other defined events. Claim deadlines run from the end, so the date matters.
Find Out Where You Stand
Whether you qualify as an adult interdependent partner drives property, support, estate rights, and deadlines, and borderline cases turn on details. William Aadil Musani practiced corporate law, tax law, and mergers and acquisitions before founding Cunningham Family Law, and brings that financial lens to common-law separations. 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 →