How to Protect a Family Inheritance from the Heir’s Spouse (Son-in-Law or Daughter-in-Law)-The Importance of the Clause of Non-Communicability in Wills and Donations

1. What is the clause of non-communicability?

The clause of non-communicability is a provision included in donations or wills through which the donor or testator determines that certain assets shall not be communicated to the beneficiary’s spouse. As a result, such assets remain exclusively part of the heir’s or donee’s personal estate, regardless of the matrimonial property regime.

In practice, this means that even if the heir is married under a universal community regime or a community of acquisitions, the assets subject to the clause will not form part of the couple’s common property. This exclusion is particularly relevant in the event of divorce, judicial separation, or death of the spouse, shielding the family estate from division or distribution.

2. A tool available to anyone

The law allows any person, when donating an asset or appointing heirs by will, to impose a clause of non-communicability. It is a widely used mechanism intended to ensure that a family asset — often of significant sentimental or patrimonial value — remains within the intended line of succession.

An asset covered by this clause is therefore “shielded” from matrimonial community, protecting it from disputes arising from the heir’s marital life.

3. Limitations: the need to specify the assets

It is important to emphasize that the clause of non-communicability cannot be drafted in abstract or generic terms. The law requires that it apply to specific, identifiable assets. For this reason, it is typically used in the context of legacies rather than the institution of heirs in abstract shares, as those do not identify specific property.

The precise identification of the asset is essential to ensure the clause’s effectiveness and enforceability.

4. Relationship with mandatory rules on asset communication

Portuguese law contains mandatory rules regarding the non-communicability of certain types of assets, as set out in Article 1733 of the Civil Code. These assets — such as those acquired by succession — are legally classified as personal property and cannot form part of the marital community.

This mandatory nature has an important consequence: the legislator prohibits spouses from establishing, in antenuptial agreements, the communicability of assets that the law declares as obligatorily personal. This is expressly stated in Article 1699(1)(d) of the Civil Code.

This strict legal framework reinforces system coherence: if certain assets are, by force of law, non-communicable even in the broadest matrimonial regime — universal community — then, a fortiori, they cannot be considered common property in more restrictive regimes such as the community of acquisitions.

5. Practical purpose and usefulness of the clause

The clause of non-communicability is an extremely useful tool of patrimonial protection, enabling donors and testators to guarantee:

• the preservation of the family estate within the intended hereditary line.
• the protection of assets in cases of marital conflict or dissolution of the heir’s marriage.
• the limitation of possible patrimonial interference by spouses with children from previous relationships.
• legal certainty in the management and transmission of assets.

More than a mechanism of mistrust towards the heir’s spouse, the clause constitutes a legitimate patrimonial planning tool, widely recognized by law and case law.

6. Establishing a fideicommissum as an additional mechanism of protection

Beyond the clause of non-communicability, the Portuguese legal system provides another particularly effective mechanism to ensure that a certain asset does not form part of the heir’s spouse’s inheritance, even in the event of the heir’s death: the ordinary fideicommissary substitution, provided for in Articles 2286 to 2295 of the Civil Code.

The Civil Code permits the ordinary fideicommissum provided that:
(i) it is limited to one degree (Portugal prohibits perpetual or multi-generational fideicommissa to prevent assets from remaining “locked” for generations);
(ii) it aims to preserve assets within the family.

This mechanism is especially useful where ascendants wish to safeguard an asset — whether movable or immovable — from risks arising from the heir’s marital life, ensuring that it remains within the direct family line regardless of death, divorce, or disputes involving the heir’s spouse.

A fideicommissum operates through the designation of:

• a fiduciary: the first beneficiary (e.g., the daughter) who receives the asset but with restrictions on disposal.
• a fideicommissary: the final beneficiary (e.g., the grandchildren) to whom the asset must pass upon the fiduciary’s death.

The transfer to the fideicommissary occurs automatically by virtue of the testator’s will and outside the fiduciary’s estate.

When properly established, the fideicommissum produces the following effects:

1. The asset does not form part of the fiduciary’s estate.
   Thus, if the daughter dies, the asset does not enter her succession, preventing the surviving spouse from receiving it through intestate or testamentary succession.
2. The fiduciary’s spouse has no rights over the asset.
   The fideicommissary’s right prevails over that of the widowed spouse, who cannot claim any statutory share or community right over that specific asset.
3. The fiduciary cannot alter the destination of the asset.
   Unless expressly authorized by the testator, the fiduciary may not dispose of or encumber the asset in a way that frustrates the fideicommissum.

This protection may be strengthened through a clause of inalienability (Article 953 of the Civil Code), provided that a legitimate reason exists — typically the protection of family assets.

Example:
A grandfather states in his will that:

• he leaves a property to his daughter (fiduciary);
• upon her death, the property shall pass automatically to the grandchildren (fideicommissaries).

In such case:

• the daughter enjoys the asset during her lifetime but may be restricted from disposing of it if an inalienability clause applies;
• the asset does not enter her estate, ensuring that the son-in-law does not inherit any part of it;
• upon her death, the property transfers directly to the grandchildren;
• the son-in-law cannot oppose the transfer, whether based on statutory inheritance rights or matrimonial property rules.

The fideicommissum, limited to one degree and aimed at preserving family assets, is a robust and effective legal tool to ensure that certain assets are not inherited by the son- or daughter-in-law, thereby guaranteeing their retention within the bloodline according to the testator’s wishes.

Given the complexity and legal implications of these matters, it is essential to seek guidance from experienced Family Law professionals, such as Belzuz Abogados S.L.P. – Portugal Branch.