Cohabitation, defined by Article 515-8 of the Civil Code as a de facto union "characterized by a common life presenting a character of stability and continuity between two persons, of different sexes or of the same sex," escapes the formalism of matrimonial or contractual institutions. Nevertheless, it remains a living arrangement that raises patrimonial and personal interests, for which contractual arrangements are sometimes necessary. In the absence of a specific legislative framework, the cohabitation agreement falls under the summa divisio of contractual law and is situated within the broader framework of contract law governed by Articles 1101 and following of the Civil Code.

Legal Foundations of the Cohabitation Agreement

Under the principle of contractual freedom provided for in Article 1102 of the Civil Code, cohabitants can, subject to compliance with public order provisions, organize the terms of their common life through a contract. This contract may cover the management of jointly acquired property, contributions to the costs of common life, and even, to a certain extent, the consequences of the termination of the cohabitation. The cohabitation agreement is inspired by the law of contractual obligations and borrows certain principles from the Civil Solidarity Pact regime without necessarily adopting its specific normative force.

In this regard, it is analyzed as an unnamed contract, governed by the common law provisions of contracts. While the adage "pacta sunt servanda" fully applies to the cohabitation agreement, it is still necessary to delineate its scope. It is accepted that cohabitants can stipulate clauses regarding: the distribution of current expenses, the methods of acquisition and management of common property, particularly in undivided ownership, governed by Articles 815 and following of the Civil Code, as well as the occupation of the common residence in the event of a breakup. However, the cohabitation agreement finds its limits in respect for public order principles.

Thus, a clause providing for an obligation of fidelity or a penalty in the event of a breakup would be deemed null and void, in accordance with established case law that prohibits any infringement on individual freedom.

The cessation of cohabitation leads to the extinction of the agreement. While the breakup is free, it may nonetheless give rise to compensation in the case of proven fault under Article 1240 of the Civil Code, particularly when one of the cohabitants has knowingly deceived the other about the durability of the relationship.

The restitution of undivided property is subject to the common law of undivided ownership, and any potential compensation for one of the cohabitants may be considered in the case of unjust enrichment.

Legal Regime and Opposability to Third Parties

The cohabitation agreement takes on the nature of a synallagmatic contract when it creates reciprocal obligations between the parties. In practice, it can be concluded under private signature or take the form of an authentic deed before a notary, which grants the obligations it contains increased enforceability res judicata.

However, its opposability to third parties remains limited. Unlike the PACS, which confers a legal status under Article 515-1 of the Civil Code specific to partners, the cohabitation agreement produces effects only inter partes. As a result, third parties, particularly creditors, are not bound by the stipulations of the agreement unless they provide evidence of a specific contractual commitment.

In Conclusion

Far from being a mere moral commitment, the cohabitation agreement constitutes a relevant legal tool for organizing patrimonial and personal matters. It allows cohabitants to address the absence of a legal regime by framing the financial and material aspects of their union.

However, its effects clash with public order imperatives and the lack of legal recognition as a status. A reform of cohabitation law would, in this sense, deserve to be considered in order to harmonize its effects with other forms of union recognized by positive law.

Written by Antoine Aufrand — Partner Figen AI