Can cohabitation automatically make the survivor an heir? The intestate succession of Catalan stable partnerships before the Constitutional Court
The “cuestión de inconstitucionalidad” 8613‑2024 —a court's reference on the constitutionality of a statute—, admitted by the “Tribunal Constitucional”, Spain's Constitutional Court, and still pending, has placed the intestate succession rights of Catalan unmarried couples at the centre of the debate. The model of the “Código Civil de Cataluña” —the Catalan Civil Code, the CCCat— constitutes a “pareja estable”, a stable partnership, automatically by cohabitation and confers on the surviving cohabiting partner the status of heir on intestacy in the absence of descendants, placing him or her on the same footing as the surviving spouse. This article examines the scope of that assimilation, the problems of evidence and of personal autonomy to which it gives rise, the conflict between parents and cohabiting partner and the possible effects of a declaration of unconstitutionality, should one be made, on successions already opened, in a context of high potential for litigation.
Since the enactment of Book Two and Book Four of the Catalan Civil Code, the Catalan rules on stable partnerships and their succession rights have been one of the most distinctive features of Catalonia's own civil law. The progressive assimilation of marriage and stable partnership, in family matters as well as in matters of succession, culminates in article 442‑3.2 of Book Four, which provides that, where the deceased dies without descendants, the estate goes to the surviving spouse or to the cohabiting partner in a stable partnership, the parents retaining their forced share. That automatic attribution of the status of heir on intestacy to the surviving cohabiting partner, based on the mere existence of a stable partnership constituted by cohabitation, has been challenged before the Constitutional Court by way of the constitutional reference 8613‑2024, admitted for consideration and still awaiting decision in 2026. The heart of the debate is whether cohabitation, legally defined as a stable partnership, can automatically make the survivor an heir, without the need for an express act of testamentary intention, and whether that is consistent with the personal autonomy of article 10 CE —the “Constitución Española”, the Spanish Constitution— and with the constitutional system of sources of law.
The starting point lies in the definition of a stable partnership in article 234‑1 of the Catalan Civil Code. That provision treats as a stable partnership two persons who live together in a community of life analogous to marriage in any of the following cases: where the cohabitation lasts for more than two uninterrupted years, where the couple have a child together during the cohabitation, or where they formalise the relationship by public deed. A stable partnership is therefore constituted automatically in cases of prolonged cohabitation or of a child in common, without the need for registration or for express formalisation, although the public deed and the “Registro de parejas estables de Cataluña”, the Catalan register of stable partnerships, afford routes to enhanced proof. This automatic constitution has consequences in many fields, among them intestate succession.
Article 441‑2 of Book Four, in regulating the statutory calls to the succession on intestacy, provides that the estate is devolved, in the absence of descendants, to the surviving spouse or to the surviving cohabiting partner in a stable partnership, on the terms and within the limits laid down by the Code, without prejudice to forced shares. Article 442‑3 gives that attribution concrete form, providing that, where the deceased dies without descendants, the estate goes to the surviving spouse or to the cohabiting partner in a stable partnership, the parents retaining their forced share. The stable partnership is thus placed on the same footing as marriage for the purposes of intestate succession, so that prolonged cohabitation or the existence of a child in common may make the survivor an heir on intestacy, relegating the deceased's parents to the position of forced heirs (“legitimarios”).
This assimilation has been welcomed by much of Catalan civil-law academic commentary, which has seen in it a recognition of the diversity of family models and a protection of the social reality of unmarried couples. Intestate succession, on this model, is built on the idea that, in the absence of descendants, the person with whom the deceased shared his or her life in a community analogous to marriage is normally the one who best embodies the continuity of his or her personal and financial plans. The stable partnership, constituted by cohabitation, becomes the holder of succession rights on intestacy, without the need for the deceased to have made a will.
The constitutional reference 8613‑2024 nevertheless brings out the tensions which this model generates from a constitutional point of view. The Constitutional Court has admitted for consideration the reference raised in respect of articles 234‑1.a and 442‑3.2 CCCat, precisely in relation to the automatic constitution of a stable partnership by cohabitation and its consequences for intestate succession. Although no decision has yet been given, the admission of the reference indicates that the Court considers that there is a significant legal issue, one which may turn on the personal autonomy of article 10 CE, on the principle of equality of article 14 CE and on the system for the distribution of competences in civil matters.
One of the central issues in the debate is personal autonomy. Article 10 CE proclaims the dignity of the person, the inviolable rights inherent in the person and the free development of personality as the foundation of political order and of social peace, and requires the rules relating to fundamental rights to be interpreted in accordance with the Universal Declaration of Human Rights and the international treaties ratified by Spain. The question is whether the automatic constitution of a stable partnership by cohabitation, with effects on intestate succession, respects the free development of personality or whether, on the contrary, it imposes a family and succession model on persons who have decided not to marry and who may not wish their cohabiting partner to be their heir in the absence of a will.
Critical academic commentary has pointed out that the automatic assimilation of cohabitation and stable partnership, with effects on succession, may impair the autonomy of those who choose not to formalise their relationship and not to subject it to the matrimonial regime. Intestate succession, on this model, becomes an extension of the legislature's family policy, which presumes that the deceased's intention is to benefit the cohabiting partner, without the need for an express declaration. The constitutional reference may raise the question whether that presumption is compatible with respect for the freedom not to marry and not to constitute a stable partnership in the legal sense, and whether the automatic constitution of a stable partnership by cohabitation ought not to be confined to social-protection purposes, without extending to intestate succession.
A further central issue is the conflict between parents and cohabiting partner. Article 442‑3.2 CCCat provides that, where the deceased dies without descendants, the estate goes to the surviving spouse or to the cohabiting partner in a stable partnership, the parents retaining their forced share. This means that the deceased's parents, who under the general regime of the Spanish national Civil Code would be called as heirs on intestacy in the absence of descendants and of a spouse, are in Catalonia relegated to the position of forced heirs where there is a cohabiting partner in a stable partnership. The constitutional reference may call into question whether that automatic relegation of the parents, based on the mere existence of prolonged cohabitation, is consistent with the principle of equality and with the protection of the family in the broad sense.
The potential for litigation is high. In practice, proof of the cohabitation and of the existence of a stable partnership may be complex. Article 234‑1 CCCat defines a stable partnership by reference to cohabitation for more than two years, to a child in common or to a public deed, but establishing prolonged cohabitation calls for evidence of fact, such as the “empadronamiento” (registration on the municipal roll of inhabitants), tenancy agreements, joint bank accounts and the testimony of neighbours and relatives. In intestate successions, the deceased's parents may challenge the surviving cohabiting partner's status as a stable partner, arguing that the cohabitation did not reach two years, that there was no community of life analogous to marriage or that the relationship was merely one of friendship or of cohabitation out of necessity. The evidential burden and the court's assessment of the cohabitation become decisive.
The constitutional reference may also address the relationship between the automatic constitution of a stable partnership and the Catalan register of stable partnerships. That register, created by Decree-Law 3/2015 and regulated by Order JUS/44/2017, is declaratory and not constitutive, so that the existence of the stable partnership may be established by other means of proof. Registration nevertheless affords enhanced proof of the stable partnership and may facilitate the attribution of succession rights. The question is whether automatic constitution by cohabitation, without the need for registration, is compatible with legal certainty and with the requirement of certainty in matters of succession, or whether some form of formalisation ought to be required for cohabitation to have effects on intestacy.
From the point of view of legislative competence, the debate is framed by article 149.1.8 CE, which reserves to the State competence over civil legislation, without prejudice to the preservation, amendment and development by the autonomous communities of their own civil law, whether “foral” or special. Catalonia, by virtue of article 129 of its Statute of Autonomy, has exclusive competence in civil law, save as regards the matters reserved to the State. The rules on intestate succession and on the succession rights of stable partnerships fall within that field of competence. The constitutional reference may raise the question whether the automatic assimilation of cohabitation and stable partnership, with effects on succession, respects the limits of the autonomous community's competence and the constitutional framework of the family and of succession.
A particularly delicate aspect is the effect of any declaration of unconstitutionality on successions already opened. Article 38 of the “Ley Orgánica del Tribunal Constitucional” —the LOTC, the Constitutional Court Act— provides that judgments given in proceedings challenging the constitutionality of legislation have the force of res judicata, bind all public authorities and produce general effects from their publication in the “Boletín Oficial del Estado”, Spain's official gazette. Article 40 adds that judgments declaring statutes unconstitutional do not permit the reopening of proceedings concluded by a judgment having the force of res judicata, save in criminal or penalty proceedings in which the nullity of the rule applied entails a reduction of the penalty or sanction or the exclusion of liability. In civil matters, a declaration that articles 234‑1.a and 442‑3.2 CCCat are unconstitutional, were it to be made, would not permit the reopening of successions already settled by a final judgment, but it could affect successions in progress and situations that have not come before the courts.
The succession opens at the moment of the deceased's death, at the place of his or her last domicile, under article 411‑2 CCCat. The law applicable to the succession is the law in force at that moment, in accordance with the first transitional provision of Book Four, which provides that successions opened and wills made after the entry into force of Book Four are governed by its provisions. A declaration that the provisions on stable partnerships and intestate succession are unconstitutional could raise the question whether it affects only successions opened after the judgment or also successions opened earlier but not concluded. The Constitutional Court's case-law on the temporal effects of its judgments and the interpretation of articles 38 and 40 LOTC will be decisive.
In practice, a finding of unconstitutionality could require the statutory call to the succession in the absence of descendants to be reinterpreted, restoring to the deceased's parents the status of heirs on intestacy where there is no spouse, and relegating the cohabiting partner to a different position, perhaps one of rights of protection or of maintenance, but not that of automatic heir. This would have a significant impact on estate planning and on litigation, particularly in the successions of elderly people who have lived together for years without marrying and without making a will.
While the constitutional reference remains pending, the rules of the Catalan Civil Code currently in force continue to apply. Legal practitioners must therefore advise their clients having regard both to the rules in force and to the uncertainty flowing from the constitutional proceedings. In practice, this counsels active estate planning: those who live together in a stable partnership and wish their cohabiting partner to be their heir may reinforce that intention by making a will, and so avoid relying exclusively on the call to the succession on intestacy; those who do not wish their cohabitation to have effects on succession may make a will to the contrary, within the limits of forced shares, or formalise their relationship in some other way.
For litigation practice, the subject carries a high potential for dispute. Proof of the cohabitation, the establishment of the stable partnership, the interpretation of the real intention to constitute a partnership, the working out of the personal autonomy of article 10 CE and the conflict between parents and cohabiting partner will be central elements in succession disputes. The Constitutional Court's eventual judgment, whichever way it goes, will mark a turning point in the intestate succession of Catalan stable partnerships, and will call for a review of academic commentary and of judicial practice.
In short, the question whether cohabitation can automatically make the survivor an heir on intestacy, without an express act of intention, is today before the Constitutional Court and is one of the most significant issues in the law of succession in Catalonia. The answer given will affect not only the technique of intestate succession but also the constitutional conception of personal autonomy, of the family and of the diversity of models of living together, and it will have immediate practical effects on estate planning and on litigation concerning unmarried couples.
