Adult Child of a Portuguese Citizen: How to Apply for Citizenship

In short: anyone born in Brazil to a Portuguese father or a Portuguese mother can apply for Portuguese citizenship at any age, even after 18. There is no language or culture test, there is no need to live in Portugal, and the father or mother does not need to be alive. What decides the application is having the right documents and using the right filing channel.

Organic Law 1/2026 (Lei Orgânica), in force since May 19, 2026, tightened the rules for grandchildren but did not create tests for children of Portuguese citizens. It did, however, change some procedural details that adults need to know. Below, we explain in plain language how to apply, which documents to gather, where to file and which mistakes to avoid.

What the law says

The rule is in Art. 1(1)(c) of the Nationality Act (Law 37/81). It says that children of a Portuguese mother or a Portuguese father born abroad are Portuguese by origin if they do one of two things:

• declare that they wish to be Portuguese; or
• register the birth in the Portuguese civil registry. In everyday language, this is often called "birth transcription": the birth registered in Brazil also becomes part of Portugal's records.

The Portuguese Nationality Regulations (Regulamento da Nacionalidade Portuguesa) call this application "attribution of citizenship by effect of will" (Art. 8). In simple terms:

• Attribution means that citizenship is recognized from birth. You are treated as Portuguese by origin, not as someone who became Portuguese later (Art. 11 of the Nationality Act).
• By effect of will means that it is you who decides to apply. If you are an adult, you make the declaration yourself.

In the end, you will have a Portuguese birth record (assento de nascimento), which is the birth registration in Portugal. This is what proves citizenship (Art. 21(4) of the Nationality Act). You do not lose your Brazilian nationality: since Constitutional Amendment 131/2023, Brazilians only lose their nationality if they make an express request to the Brazilian authorities (Art. 12, § 4, II, of the Constitution).

Example: Mariana is 34 years old and was born in Campinas. Her father, António, was born in Porto and has lived in Brazil since he was young. Mariana can apply for Portuguese citizenship now, as the daughter of a Portuguese citizen. Her age does not matter, nor does the fact that she has never been to Portugal.

What is not required of the child

The 2026 reform created culture, history and State organization tests for grandchildren (Art. 1(3), which applies only to subparagraph (d)). For the child of a Portuguese citizen, the law does not require:

• living in Portugal;
• a language or culture test;
• proof of a connection with Portugal;
• that the Portuguese father or mother be alive.

It also makes no difference whether the Portuguese parent is the father or the mother.

Three points that need attention

1. The link with the father or mother must have been recognized before age 18

Art. 14 of the Nationality Act says that, as a rule, only parentage (the legal link with the father or mother) established while the child was a minor counts for citizenship. If the Portuguese father only recognized the child after age 18, that recognition only counts for citizenship if it came from court proceedings, once the decision has become final. In that case, the citizenship application must be filed within three years. If the decision was issued by a Brazilian judge, the recognition (review) of the judgment in Portugal may be needed first.

Example: João was registered by his mother only. When he was 25, his Portuguese father went to the notary's office and recognized him as his son. Under Portuguese law, this recognition made at a notary's office after age 18 does not count for citizenship.

2. You must prove that your father or mother is Portuguese

The application requires proof of the Portuguese citizenship of one of the parents (Art. 8(2) of the Regulations). If the father or mother was also born outside Portugal and does not yet have his or her citizenship registered, that must be sorted out first. There are also older cases that need review: under the Portuguese law of 1959, a Portuguese citizen who voluntarily became a naturalized Brazilian lost Portuguese citizenship. The current law deals with these situations in Arts. 30 and 31, and the result depends on what is annotated in the Portuguese birth record.

3. The father or mother may be asked to respond

When the child is an adult, the office may, if it considers it necessary, send a letter to the Portuguese father or mother, who will have 30 days to respond. This does not happen when the father or mother has died and the death is annotated in the Portuguese birth record (Art. 8(3) and (4) of the Regulations).

Document checklist

Based on the official guide from Portugal's Ministry of Justice and Art. 37 of the Regulations, gather:

• Your full-content birth certificate (inteiro teor), preferably issued as a photocopy of the registry book (reprográfica). Full content means a complete copy of the record, with all annotations.
• Portuguese birth certificate of the father or mother. It may be waived if you provide the registry office (conservatória, the Portuguese registry), the number and the year of the record (Art. 37(4) of the Regulations).
• Valid identity document.
• IRN declaration form (Institute of Registries and Notary, the body that reviews applications), signed by you in front of the official or, if you send it by mail, with a notarized signature.
• Power of attorney, if the application is filed by a lawyer or solicitor (Art. 31 of the Regulations).

Brazilian certificates do not need translation for use in Portugal (Art. 37(2) of the Regulations). But they do need the Hague Apostille, a seal issued by a notary's office that confirms abroad that the document is authentic. It is provided for in the Apostille Convention (Decree 8,660/2016) and is issued through the CNJ system. See more on the page about apostille and translation of documents.

In some cases, the transcription of the parents' marriage in Portugal must be done first. This usually happens when both parents are Portuguese or when the Portuguese parent is the mother and she was not the one who declared the birth at the notary's office.

Where to apply

Official sources: Portuguese citizenship, Submit a citizenship application and Citizenship application by mail. The IRN form for children over 18 states a fee of €175. Confirm the amount and method of payment when you apply.

Step by step

1. Find your father's or mother's Portuguese birth record. Check whether there are annotations of marriage, death or loss of citizenship. If it is hard to find, document research is usually the first step.
2. Request your full-content certificate from the Brazilian notary's office and have it apostilled.
3. Compare the details. Names and dates on your certificate must match those in the Portuguese birth record. If there is an error, it must be corrected first, through a correction of the civil record.
4. Check whether your parents' marriage needs to be transcribed.
5. Choose where to file and fill in the right form.
6. Pay the fee and file the application. For applications sent by mail, the IRN emails a code to check its progress.
7. Respond to notices. If a document is missing, you are notified and have 30 days to complete the file (Art. 41(1) of the Regulations). Missing this deadline may lead to the application being refused.
8. After registration, apply for the Citizen Card and Portuguese passport.

How long does it take?

No timeframe can be promised. The Regulations provide for 30 days for the first review and 60 days for the decision once the file is complete (Art. 41). In practice, the wait is usually much longer. In exceptional cases, with a proven reason, an urgency request may be considered.

Common mistakes

• Thinking you are too old. There is no age limit for children.
• Using the wrong certificate: a short-form certificate instead of a full-content one, or an apostille on a certified copy instead of on the certificate itself.
• Different names or dates between your certificate and your father's or mother's birth record. The apostille does not correct errors.
• Relying on a recognition of paternity made after age 18 at a notary's office. It does not count for citizenship (Art. 14).
• Forgetting the transcription of the parents' marriage, when it is required.
• Booking the consulate planning to send an attorney-in-fact. Since May 19, 2026, the declaration at the consulate requires your presence.
• Sending it by mail without a notarized signature or without payment. This may lead to the application being returned or refused (Art. 32(3) of the Regulations).

• Law 37/81 (Nationality Act), consolidated version — Arts. 1(1)(c) and 1(3); 11; 14; 17; 21(4); 30 and 31
• Organic Law 1/2026 (Lei Orgânica), of May 18 (Arts. 2, 4, 7 and 8; republication of Law 37/81) — Diário da República 95/2026
• Portuguese Nationality Regulations — Decree-Law 237-A/2006 (Arts. 8, 31, 32, 37 and 41)
• Justiça.gov.pt — Born abroad as the child of a Portuguese citizen (official guide)
• Justiça.gov.pt — Submit a citizenship application
• Justiça.gov.pt — Portuguese citizenship: how and where to apply
• Justiça.gov.pt — Citizenship application by mail
• Federal Constitution, Art. 12, § 4, II — Constitutional Amendment 131/2023
• Decree 8,660/2016 (Decreto) — Apostille Convention
• CNJ — Hague apostille

Sene & Araújo Sociedade de Advogados team. Content prepared and reviewed by the firm's lawyers, admitted to the Brazilian Bar Association (OAB) and the Portuguese Bar Association (Ordem dos Advogados), with offices in São Paulo and Albufeira. The provisions cited were checked against the official sources listed above. Meet the team.