Prenuptial Agreements: Planning and Security in Marriage

The celebration of marriage involves not only a personal choice but also the establishment of a legal framework with significant property implications. Among the instruments provided by law to regulate this aspect is the prenuptial agreement, which allows the parties to the marriage to determine, before the wedding, the property regime and other rules regarding the management of shared assets.

Marriage represents a decisive moment in people’s lives. By choosing to build a life together, we are not only affirming an emotional bond: we are also assuming a set of legal implications that will shape the marriage, with particular impact on the property and financial sphere. To ensure greater predictability in property matters, the prenuptial agreement can serve as an important instrument to clarify, from the outset, the terms that will govern the marriage.

In this regard, the prenuptial agreement “is an accessory contract of marriage that must necessarily be executed before it and which serves primarily to choose the property regime” (see Article 1698 of the Civil Code). In this way, the prenuptial agreement allows the property regime of the marriage to be defined from the very beginning.

In Portugal, there are three regimes:

1. Communion of acquired property: only the property acquired after the marriage belongs to the couple;
2. General community of property: as a general rule and without prejudice to exceptions provided by law, property acquired before and after the marriage becomes joint;
3. Separation of property: each spouse retains exclusive ownership of their assets, whether acquired before or after the marriage.

Through the agreement, the parties can choose one of these regimes and, within legal limits, adjust certain rules to their reality. In the absence of an agreement, the regime of communion of acquired property applies by default. Beyond choosing the regime, the agreement can also regulate other property matters, such as the management of assets or responsibility for debts.

“To execute a prenuptial agreement, the parties must do so before the marriage and in the legally required form.”

However, there are legal limits: it is not permitted to waive fundamental marital duties or infringe parental rights. Generally, the agreement is executed either by notarized public deed at a notary’s office or by declaration before the Civil Registry, ensuring that the agreement is properly formalized and registered.

After its execution, the marriage must take place within a maximum period of one year, under penalty of the agreement becoming void. Thus, even though prenuptial agreements sometimes face social resistance - being occasionally associated with mistrust or anticipation of marital failure - they actually constitute a mechanism of responsible planning. By enabling proper management of assets according to each couple’s reality, the parties contribute to more balanced, stable, and legally secure relationships.