Keeping Spanish nationality when you become a US citizen

This is the procedure that has cost the most nationalities and gets talked about least: a Spaniard who becomes a US citizen loses Spanish nationality unless they declare within three years that they wish to keep it.

The declaration is made before the Civil Registry, and anyone living in the United States makes it at their consular office. It is free.

Why Americans are affected

The Civil Code exempts Spaniards by origin who acquire the nationality of Ibero-American countries, Andorra, the Philippines, Equatorial Guinea, Portugal or France. With those countries there is a treaty or a legal provision and nothing needs doing.

The United States is not on the list. So a Spaniard who takes the US oath starts a three-year clock that day.

The other case: born abroad to parents born abroad

There is a less known case, very common in the diaspora: a Spaniard born abroad to parents also born abroad, whose country of residence gave them its nationality while they were a minor. That person must declare their wish to keep Spanish nationality before turning 21.

It is the small print that explains why whole families discover at thirty that they had legally stopped being Spanish.

Express and tacit conservation

The express route is the personal declaration before the Civil Registry. The tacit one can arise from acts that involve exercising rights or duties as a Spaniard —renewing a passport, voting, registering— but the consular office decides whether they count.

Do not rely on it: the express declaration is the only one nobody argues with.

What to bring

Valid foreign passport, Spanish passport and DNI even if expired, proof of address in the district and a full birth certificate less than a year old. Plus your US naturalization certificate, apostilled and sworn-translated.

If you are a married woman and the naturalization certificate or passport shows your married surname, you also need the marriage certificate, apostilled and translated.

And if the deadline has passed

Then the procedure is not conservation but recovery, a different declaration. Emigrants and their children are not required to have legal residence in Spain to recover it; someone who was not Spanish by origin also needs government authorization.

Details verified on 8 September 2026.

consuladosespana.us is an independent guide to Spain's consular offices in the United States. We are not the Embassy, any Consulate General, or the Spanish Ministry of Foreign Affairs.

We do not book or sell appointments: consular appointments are free. Details are checked regularly and can change without notice.