Prenuptial Agreements in Portugal for International Couples

Quick answer

A Portuguese prenuptial agreement, `convenção antenupcial`, is the legal instrument used before marriage to choose or structure the matrimonial property regime within the limits of the law.

If Portuguese law applies and no valid prenup selects another regime, the default is normally `comunhão de adquiridos`, community of acquired property.

For international couples, a prenup should not be treated as a Portuguese formality in isolation. You also need to ask which country's law will govern the matrimonial property regime and whether a separate choice-of-law agreement is appropriate.

What can a Portuguese prenup do?

The future spouses can use a prenup to choose one of the principal Portuguese regimes:

• separation of property
• general community of property
• community of acquired property where a formal agreement is useful
• a customised regime within statutory limits

A customised regime can adapt parts of the property structure to the couple's objectives, but the freedom is not unlimited.

Portuguese law does not allow a prenup to rewrite fundamental spousal duties or simply contract out of mandatory rules on the administration of marital property.

When is a prenup especially relevant?

A prenup deserves serious consideration when:

• one person owns significant assets before marriage
• one person owns a company or professional practice
• one or both spouses expect to buy Portuguese property
• one person has substantial debt or business risk
• the spouses have different nationalities
• the couple will live outside Portugal
• there are children from a previous relationship
• the couple has assets in several countries
• one or both spouses expect significant inheritances
• a foreign prenup already exists and must fit a Portuguese legal context

The objective is not automatically to create separation of property.

The objective is to understand the legal result before the marriage and deliberately choose the structure that fits the couple.

How is a Portuguese prenup made?

Portuguese law recognises a prenup when it is made in the required form.

It can be concluded:

• by a declaration before a civil registry official
• by public deed

The agreement must be made before the marriage.

It also needs the required registration to produce effects against third parties.

A prenup that exists only as a private document between the couple is not the same thing as a valid Portuguese `convenção antenupcial`.

Timing matters

Do not leave the property regime until the ceremony week.

The agreement is part of the legal architecture of the marriage.

It should be designed after the couple has clarified:

• applicable law
• current assets
• expected future acquisitions
• companies and investments
• debt exposure
• inheritance expectations
• intended Portuguese property purchases

Portuguese law also provides that a prenuptial agreement lapses if the marriage is not celebrated within one year.

Can we sign it after the wedding?

As a general rule under Portuguese law, no.

The matrimonial property regime is subject to a principle of immutability after marriage, apart from specific statutory exceptions.

A couple should therefore not plan on marrying under the default regime and "fixing it later" with a private postnuptial agreement.

If the couple is already married, the analysis changes from planning a prenup to identifying the existing applicable regime and any legal mechanisms available for the specific issue.

Is a prenup always optional?

No.

There are situations in which Portuguese law itself imposes separation of property.

For example, the Civil Code imposes separation of property when a future spouse has reached the statutory age of 60.

In that situation the couple is not simply choosing between all standard regimes.

What if one of us has children already?

Portuguese law places restrictions on the freedom to choose certain community arrangements when a future spouse already has children.

This is exactly the type of issue that should be identified before a standard registry form is treated as sufficient.

For blended families, the property-regime decision also needs to be considered alongside inheritance planning.

International couples need two separate questions answered

For a couple with different nationalities, residence abroad or assets in several countries, two different legal questions can exist:

Regulation (EU) 2016/1103 allows spouses within its scope to choose applicable law from defined connecting laws.

Without a valid choice, the Regulation applies its own hierarchy, starting generally with the first common habitual residence after marriage.

A Portuguese prenup should therefore be coordinated with the cross-border applicable-law analysis instead of assuming that the location of the wedding automatically settles the issue.

Does a foreign prenup work in Portugal?

Do not assume either yes or no from the title of the document.

A foreign agreement has to be analysed for:

• the law governing the matrimonial property regime
• formal validity
• material validity
• its scope
• registration or publicity requirements
• its effects against third parties
• Portuguese mandatory rules that remain relevant to a Portuguese transaction

If you already have a foreign prenup, review it before a Portuguese property purchase or dispute rather than discovering its effect at the deed or during divorce.

What should a pre-marriage review cover?

For an international couple, the review should map:

• citizenships
• habitual residence
• expected country of residence after marriage
• existing assets
• Portuguese and foreign real estate
• business interests
• liabilities
• children from previous relationships
• wills and inheritance planning
• intended property purchases
• the proposed matrimonial regime
• applicable-law choice

The result should be a structure the couple understands, not simply a document to sign.

Related guides

Matrimonial property regimes in Portugal

Buying property in Portugal as a married couple

Marriage in Portugal for foreign and non-resident couples