Parental union and its patrimony: new considerations for practitioners

Since June 30, 2025, the Civil Code of Québec has provided for a new legal framework applicable to certain de facto spouses: parental union. Without constituting a marriage or civil union, this regime automatically gives rise to certain legal effects, including the creation of a parental union patrimony.

For practitioners, this reform calls for new considerations. Parental union must now be taken into account not only in the event of a separation, but also in the context of cohabitation agreements, estate planning and certain real estate transactions. It also calls for greater collaboration between lawyers and notaries, as the legislature has required certain agreements that modify or exclude the parental union patrimony to be executed by notarial act.

Identifying a parental union… and its patrimony

Under article 521.20 C.C.Q., a parental union is formed when de facto spouses become the parents of the same child, or when the parents of the same child subsequently become, or once again become, de facto spouses. Certain limitations must, however, be kept in mind.

Where one of the spouses is already married, in a civil union or in a parental union, a new parental union may only be formed once that prior union has been dissolved or ended. In addition, a parental union cannot be formed between persons who are, in relation to one another, an ascendant, a descendant, a brother or a sister.

The regime applies automatically to spouses who become the parents of the same child on or after June 30, 2025, while those who were already the parents of a common child before that date may choose to become subject to it. Practitioners must therefore determine not only whether the conditions for the formation of a parental union have been met, but also the precise date on which the union was formed.

A parental union entails the creation of a parental union patrimony. Like the family patrimony, it is established regardless of which spouse holds title to the property comprising it. Its scope is, however, more limited. Article 521.30 C.C.Q. covers the family residences or rights conferring the use of such residences, the movable property furnishing or decorating them and serving for household use, as well as the motor vehicles used for family travel. Unlike the family patrimony, it does not include rights accrued under a retirement plan or earnings registered under the Québec Pension Plan.

Also excluded from the patrimony are property received by one of the spouses by succession or gift, before or during the union, as well as property belonging to a minor spouse until that spouse reaches the age of majority. These exclusions are in addition to the deductions provided for upon liquidation of the patrimony. Thus, where property forming part of the patrimony already belonged to one of the spouses at the time the parental union was formed, article 521.36 C.C.Q. allows, among other things, the net value of the property at the time the patrimony was constituted, as well as the increase in value attributable to that net value during the union, to be deducted from its net value upon partition, in accordance with the terms set out in the Code.

As with the family patrimony, title to the property is therefore not determinative: a residence owned exclusively by one spouse may nevertheless form part of the parental union patrimony, and its value may be taken into account upon liquidation.

Contractual autonomy

The legislature affords spouses considerable autonomy with respect to their parental union patrimony. Article 521.31 C.C.Q. allows them, in particular, to modify its composition, either by adding certain property or by excluding property that would normally form part of it.

Where the agreement seeks to exclude property from the patrimony, however, it must be executed by notarial act en minute, failing which it is absolutely null.

Spouses may also choose to opt out entirely from the application of the provisions relating to the parental union patrimony. Here again, article 521.33 C.C.Q. requires a notarial act en minute, on pain of absolute nullity.

Where the spouses opt out within 90 days of the beginning of the parental union, the patrimony is deemed never to have been constituted. The spouses may nevertheless opt out after this period has expired. The opt-out then takes effect on the date of the act and gives rise to a right to partition: the patrimony constituted up to that date must therefore be liquidated and, where applicable, the claim resulting from the partition must be determined.

A client who simply states that they do not wish to “be subject to the parental union patrimony” is therefore not in the same situation depending on whether the union was formed a few weeks, a few months or several years earlier.

It is also important to avoid a distinction that remains a frequent source of confusion, even among legal professionals: the parental union and the parental union patrimony are two distinct concepts. The patrimony is only one of the legal effects arising from the parental union.

Accordingly, the opt-out provided for in article 521.33 C.C.Q. applies solely to the provisions governing the parental union patrimony. It does not allow spouses to “opt out” of the parental union itself. The parental union continues to exist until one of the causes for its termination provided by law occurs, and the other legal effects associated with that status continue to apply.

This distinction is far from theoretical. It arises, in particular, in relation to the family residence: certain protections afforded to spouses in a parental union continue to apply even where they have validly opted out of the parental union patrimony. The opt-out should therefore not be presented — or understood by clients — as a complete waiver of the regime.

A new approach to collaboration

Parental union affects several areas of practice, including cohabitation agreements, property rights, estate planning and the consequences of a potential separation.

Lawyers and notaries may be called upon to advise spouses on the organization of their patrimonial relationships and to work with them to develop solutions tailored to their circumstances. Certain solutions — including the exclusion of property or opting out of the parental union patrimony — must, however, be documented by notarial act.

Parental union therefore calls for a more integrated approach to legal practice: lawyers and notaries stand to benefit from combining their respective expertise to better advise the families they serve.

This article was provided by De Grandpre Chait LLP