Common-Law Relationships in Alberta (AIP) Explained

Alberta does not use the term "common law" in its legislation; instead, unmarried couples who meet the legal test become "adult interdependent partners" (AIPs) under the Adult Interdependent Relationships Act, which since January 1, 2020 also gives them a statutory right to divide property.

Alberta does not say "common law"

Many Albertans describe an unmarried partner as their "common-law spouse," but that phrase appears nowhere in Alberta's family statutes. Alberta replaced the concept in 2003 with a defined legal status: the adult interdependent partner (AIP), created by the Adult Interdependent Relationships Act (AIRA). The change was deliberate. Rather than tying rights and obligations to marriage-like cohabitation alone, Alberta built a status around "interdependence" that can, in limited circumstances, include people who are not a couple at all.

Whether a person qualifies as an AIP matters for partner support, property division, and inheritance. It is a factual and legal question with real consequences, not a casual label.

How you become an adult interdependent partner

Under AIRA, two people become adult interdependent partners in one of three ways:

1. Three years of cohabitation. They have lived together in a "relationship of interdependence" for a continuous period of at least three years.
2. A relationship of some permanence, plus a child. They have lived together in a relationship of interdependence for less than three years, but the relationship has some permanence and they have a child together, by birth or adoption.
3. A written agreement. They sign a formal adult interdependent partner agreement, which can create AIP status immediately, without waiting for any cohabitation period, provided both parties have independent legal advice.

A "relationship of interdependence" means two people share each other's lives, are emotionally committed to one another, and function as an economic and domestic unit. Courts look at things like shared finances, a shared home, and mutual support, not just how long two people lived at the same address.

AIP status is not limited to couples

One feature that surprises people outside Alberta: an adult interdependent relationship does not have to be conjugal. AIRA allows two people who are not a couple, for example two adult relatives, or two long-term friends, to qualify as adult interdependent partners if they meet the statutory test of interdependence and are not already within a degree of relationship the Act excludes from qualifying (such as a parent and child). This is one of the clearest ways Alberta's model diverges from "common law" as most Canadians understand the term, which assumes a marriage-like couple.

Property division: the change that sets Alberta apart

For decades, Alberta's unmarried partners had no statutory property regime at all. If a relationship ended, a partner without a spot on the title had to rely on equitable doctrines like unjust enrichment, an unpredictable and expensive path.

That changed on January 1, 2020, when Alberta's Matrimonial Property Act was renamed and rewritten as the Family Property Act, extending its property division rules to adult interdependent partners for the first time. Since that date, AIPs whose relationships end are governed by the same statutory framework as divorcing married spouses, not case-by-case equitable claims.

The starting point is a presumption of equal division of family property, meaning property acquired during the relationship. Alberta courts can order an unequal division where equal division would not be just and equitable, but equal sharing is the default.

Certain property is exempt from division, including:

• Property either partner owned before the relationship began
• Gifts from a third party received during the relationship
• Inheritances received during the relationship
• Certain damage awards or insurance proceeds received by one partner alone

Exempt property is not automatically off the table forever, though. If exempt property grows in value during the relationship, for example a pre-relationship investment account that appreciates, that increase in value is divisible, generally on a just and equitable basis rather than a strict 50/50 split. The exemption protects the original value, not the growth.

A partner generally has two years from the date they knew, or ought to have known, that the relationship ended to start a property claim under the Family Property Act. Partners can also opt out of the default rules with their own written agreement.

Partner support for AIPs

Alberta's Family Law Act lets a court order partner support for an adult interdependent partner, using factors closely modelled on the spousal support factors in the federal Divorce Act. As with married spouses, a person seeking partner support must first establish an entitlement to support, before any question of amount or duration arises. Alberta courts frequently look to the federal Spousal Support Advisory Guidelines (SSAG) by analogy when setting the amount and duration of partner support, but the SSAG are advisory guidelines, not legislation, for AIPs exactly as they are for divorcing spouses. They inform a court's discretion; they do not bind it.

Claims for partner support are also subject to a limitation period, generally two years from the date the AIP relationship ended, so delaying is risky.

How an adult interdependent relationship ends

Under AIRA, a person stops being someone's adult interdependent partner, and becomes a "former" AIP, on the earliest of these events:

• The partners sign a written agreement that shows they intend to live separate and apart without the possibility of reconciliation
• The partners live separate and apart for more than one year, with one or both intending the relationship not to continue (a single reconciliation attempt of 90 days or less does not restart the clock)
• One partner marries someone else
• One or both partners obtain a declaration of irreconcilability from a court

Because the end date determines when the property and support limitation periods start running, pinning down exactly when a relationship ended can matter a great deal in a later dispute.

Estate consequences: AIPs inherit on intestacy

Alberta's Wills and Succession Act treats a surviving adult interdependent partner similarly to a surviving married spouse when a person dies without a will. If the deceased has no children, or only children from the AIP relationship, the surviving AIP generally inherits the entire estate. If the deceased also has children from a different relationship, the surviving AIP typically receives a preferential share (a set amount or a share of the estate, whichever is greater) with the remainder split with those children. An AIP loses this intestate entitlement if the couple had already separated for two years or more, or a court had already declared the relationship irreconcilable, before the death.

This is a meaningful contrast with provinces like Ontario, where a common-law partner has no automatic entitlement under intestacy law at all and must apply to court for support as a dependant instead. Marrying, or entering a new AIP relationship, generally does not revoke an existing will in Alberta the way it can in some other provinces, but AIPs who want certainty about what happens to their estate should still have a current will.

Married spouses vs. adult interdependent partners in Alberta

How Alberta compares to the rest of Canada

Alberta's approach is one of several different models Canadian provinces use for unmarried couples. Ontario gives common-law partners a right to claim spousal support after three years (or sooner with a child), but no automatic property equalization at all. British Columbia treats two years of marriage-like cohabitation as making a person a "spouse" with full property division rights, the most generous standard in the country. Alberta sits between these approaches: it kept a distinct legal label, "adult interdependent partner," rather than folding unmarried partners into the word "spouse," but since 2020 it gives AIPs a property regime nearly as complete as British Columbia's. For a province-by-province overview, see our guide to common-law relationships across Canada, and for a direct look at how Ontario's very different model works, see common-law relationships in Ontario.

Formalizing an AIP relationship

Because AIP status turns on facts (how long a couple lived together, whether they functioned as an economic unit), and because those facts can be genuinely disputed later, many couples choose to sign a written adult interdependent partner agreement rather than rely on the passage of time. A written agreement can also be used to opt out of the default property division rules and set different terms. Either way, an enforceable domestic contract generally needs to be in writing, signed, witnessed, and built on full financial disclosure. Our guide to separation agreements in Canada explains those requirements in more detail. For the broader Canada family law picture, see the family law hub.

Disclaimer: This article explains general legal concepts about adult interdependent partnerships in Alberta and is not legal advice. Whether a specific relationship qualifies as an adult interdependent partnership, and how property, support, or estate rules apply, depends on individual facts. Consult a licensed Alberta family law lawyer before relying on this information.