“Common Law” Relationships: Understanding the Differences Between Married and Unmarried Spouses in the Family Law Context

By: Dayna E. Kwasney BA, JD

In recent years, common-law relationships have become increasingly more prevalent, with a greater number of committed spouses choosing to simply cohabitate rather than get married[1]. However, a vast majority of the population remains uninformed with respect to the legal differences between common-law relationships and marriages. This blog post will attempt to outline and explain what a common-law relationship is, as well as the primary differences and similarities between the legal rights of married and unmarried spouses solely within the family law context.

The term “common-law marriage” is frequently used to describe spouses who live together, with or without children, but are not married. However, as of June 2003, with the introduction of the Adult Interdependent Relationships Act,[2] this term is no longer used in Alberta law. Rather, as per the new legislation, unmarried spouses are referred to as “adult interdependent partners.” Despite this change to the province’s terminology, the term “common-law” is still utilized by other provinces and by the federal government. For example, under the Federal Income Tax Act, if two people live together for a period of one year (as opposed to 3 years under the Adult Interdependent Relationships Act), they are considered common-law partners for income tax purposes.  

The Adult Interdependent Relationships Act outlines essentially three possible ways for an adult interdependent relationship to arise:

  1. The spouses have entered into a written Adult Interdependent Partner Agreement;

  2. The spouses have lived with each other in a “relationship of interdependence” for at least 3 consecutive years; OR

  3. The spouses have lived with each other in a “relationship of interdependence” for less than 3 years, but the relationship is of some permanence and there is a child of the relationship either by birth or adoption.

A “relationship of interdependence” is defined in the Act as a relationship outside of marriage in which two people: (a) share one another’s lives, (b) are emotionally committed to one another, and (c) function as an economic and domestic unit. To determine whether spouses function as an economic and domestic unit, all of the circumstances of the relationship must be taken into account, including:

  1. Whether or not the persons have a conjugal relationship;

  2. The degree of exclusivity of the relationship;

  3. The conduct and habits of the persons in respect of household activities and living arrangements;

  4. The degree to which the persons hold themselves out to others as an economic and domestic unit;

  5. The degree to which the persons formalize their legal obligations, intentions and responsibilities toward one another;

  6. The extent to which direct and indirect contributions have been made by either person to the other or to their mutual well-being;

  7. The degree of financial dependence or interdependence and any arrangements for financial support between the persons;

  8. The care and support of children; and

  9. The ownership, use and acquisition of property.

It is important to note that the relationship does not need to be conjugal to meet the above criteria; it can be purely platonic and still be classified as an adult interdependent relationship under the law. However, people who are related to each other by blood or adoption MUST enter into a written Agreement in order to be considered adult interdependent partners. Other restrictions include:

  1. A married person cannot become an adult interdependent partner while living with his or her spouse;

  2. A person cannot have more than one adult interdependent partner at a time;

  3. An Adult Interdependent Partner Agreement must be entered into freely by both parties without any undue influence, fraud, or duress; and

  4. A minor cannot enter into an Adult Interdependent Partner Agreement, unless the minor is at least 16 years of age, and his or her guardians have given prior written consent.

Unlike a marriage, there are no formal proceedings similar to a divorce to terminate an adult interdependent relationship. Instead, the relationship will come to an end upon the occurrence of any one of the following:

  1. The partners live separate and apart for one year;

  2. The partners marry each other, or one of the partners marries or enters into an adult interdependent relationship with a third party;

  3. The partners sign a written agreement stating that they intend to live separate and apart without the possibility of reconciliation; OR

  4. One or both of the partners have obtained a declaration of irreconcilability under the Family Law Act[3].

Spousal Support, Child Support & Child Custody

An adult interdependent partner may bring a claim for spousal support under Alberta’s Family Law Act. A married spouse may bring a spousal support claim either under Alberta’s Family Law Act or Canada’s Divorce Act[4], but for all intents and purposes, spousal support under both pieces of legislation is the same.

Similarly, with respect to child support and custody matters, the applicable laws are essentially identical for married and unmarried spouses in Alberta. Again, the only real difference is purely procedural: married spouses may make an application either under the Divorce Act or the Family Law Act, while adult interdependent partners may only apply under the Family Law Act.

Property Rights on Separation

The area of the law in which the gap between the legal rights of married and unmarried spouses is most prominent is that of property rights. In Alberta, when a marriage ends, property division is governed by Alberta’s Matrimonial Property Act[5]. Under this Act, there is a presumption of an equal division of non-exempt[6] property upon breakdown of the marriage. However, this Act solely applies to married spouses, NOT adult interdependent partners, and thus there is no automatic right to equal property division when an adult interdependent relationship ends.

The general rule for adult interdependent partners is that when the parties separate and the relationship comes to an end, each retains the property he or she personally brought into the relationship or bought and paid for during the relationship. Any property purchased jointly is to be equally shared. If one party is not satisfied with this result, and/or it would be unfair for one party to keep property he or she acquired during the relationship, it may be possible to make an application to the Court to have the property divided in a different way on the grounds of a claim for unjust enrichment.

Unjust enrichment is based on the principle that no one should be allowed to benefit or profit at another’s expense. For example, in the family law context, often one partner will stay home to look after the house and children, while the other partner works outside the home. The partner working outside the home is then able to use his or her earnings to acquire assets, save for retirement, or gain equity in a mortgaged home. In this way, although both partners contributed to the relationship, only one benefitted financially. In these sorts of situations, the Courts have stated that there must be some recognition of the non-financial contributions of the stay-at-home partner. It is important to note that the unjust enrichment remedy is not only available for adult interdependent partners; rather, it can also be utilized as a potential remedy by parties that have resided together for a much shorter time period, as well as outside the family law context altogether.  

In order to establish a claim in unjust enrichment, a claimant must prove three things: (1) a gain by one party, (2) a corresponding loss by the other party, and (3) that there was no legal reason that would justify the gain or loss (e.g., a contract of service entered into by the parties providing for the gain or loss). If the Court is satisfied that all elements of the test have been met, then the party who suffered a loss will be compensated either by a monetary award (i.e. damages), or a constructive trust, which allows the party to receive a share/interest in his or her partner’s property.

However, in addition to this traditional analysis, the Supreme Court of Canada in the 2011 landmark cases of Kerr and Baranow[7] (“Kerr”) and Vanesse v Seguin[8] (“Vanesse”), added the concept of a”joint family venture” to the legal mix. Whereas previously, parties had to show a direct link between the enrichment and a specific asset or assets in order to succeed on his or her claim for unjust enrichment, the joint family venture perspective looks at the situation as a whole.

The Supreme Court of Canada held that where both parties contribute to the accumulation of wealth, a party will be found to be unjustly enriched where he or she is allowed to keep an unequal share of the assets produced as a result of the parties’ joint efforts. Further, establishing a link between the contributions of the claimant and a specific property is no longer a requirement. As long as there is a clear link between the joint efforts of the parties and the accumulation of wealth, a claim for unjust enrichment will succeed. Ultimately, the Supreme Court decided that regardless of who actually owns the property in question (i.e. who is the titled owner), when parties make a commitment to engage in a joint family and economic venture, the wealth accumulated during the period of cohabitation will be treated by the courts as a product of the parties’ mutual labour and divided accordingly.

Whether the parties have been engaged in a “joint family venture” is a question of fact determined by assessing all of the relevant circumstances including:

  1. Mutual effort (i.e. did the parties work together and pool their assets?);

  2. Economic integration (i.e. did the parties have joint bank accounts or investments? Did they share expenses?);

  3. Actual intent (i.e. did parties hold themselves out as “partners”?); and

  4. Priority of the family (i.e. did one spouse give up a career, employment or education to care for any children of the family?).

However, the Supreme Court was careful to emphasize that mere cohabitation does not entitle a party to a share of the other’s property or to any remedy without evidence of contribution. Further, simply because a joint family venture is established does not necessarily mean that the non-titled spouse will receive 50% of the value of the specific property in question; rather, the court retains the discretion to select a certain percentage.

Closing Remarks

Although the cases of Kerr and Vanesse represented great changes for unmarried spouses in terms of equalizing property rights upon breakdown of the relationship, there is still a noticeable gap in terms of how unmarried and married spouses are treated under the law. Unmarried spouses must first establish that a “joint family venture” exists and that a claim for unjust enrichment has been made out before being entitled to a property remedy upon breakdown of the relationship, whereas married spouses are automatically entitled to an equal division of non-exempt property upon separation or divorce.

In their recent Report for Discussion, the Alberta Law Reform Institute recommended changes to the current legislation in order to bring unmarried couples in relationships of interdependence within the Matrimonial Property Act regime[9].  Recommendations include:

  1. Applying a presumption of equal division to any property acquired while the partners were living together in a “relationship of interdependence”;

  2. Exempting (i.e. excluding) property acquired by the partners before the commencement of their “relationship of interdependence” from the presumption of equal division;

  3. Confirming that Cohabitation Agreements about ownership and the division of property should continue in effect if the partners marry, unless the partners agree otherwise; and

  4. Setting the default date of valuation of property as the date on which the parties began living separate and apart.

Although these recommendations have not yet been formally implemented, they represent a changing mindset in terms of addressing the uncertainty that many unmarried spouses face regarding property division upon separation.


NOTICE TO READER: The summaries of legal rights and remedies described above are general references to the Alberta laws existing at the date of the publication and may not apply to the reader’s individual circumstances. Also, the laws may change. These legal summaries are not to be relied upon as applicable to your individual circumstances and are subject to a complete review of the facts and applicable laws in every case.


[1] Census data shows that the majority of people aged 20 to 29 expected to live in a common-law relationship prior to marriage (Alberta Law Reform Institute, “Property Division: Living Together Before Marriage”, Report for Discussion 31, October 31, 2017, https://www.alri.ualberta.ca/images/stories/docs/RFD31.pdf?utm_source=alri&utm_medium=email&utm_campaign=rfd31 ).

[2] Adult Interdependent Relationships Act, SA 2002, c A-4.5.

[3] Family Law Act, SA 2003, c F-4.5

[4] Divorce Act, RSC 1985, c 3 (2nd Supp).

[5] Matrimonial Property Act, RSA 2000, c M-8.

[6] Certain types of property are considered exempt from division under the Matrimonial Property Act. Further, growth in value of exempt property might not be distributed according to a 50/50 basis.

[7] Kerr and Baranow, 2011 SCC 10.

[8] Indexed as Kerr v Baranow, 2011 SCC 10.