The short version
- It depends on how you become Spanish. If your mother or father was Spanish when you were born, you are Spanish from birth, and Spain does not ask you to give anything up.
- Americans who naturalise in Spain must declare that they renounce their old nationality. A few groups are exempt, and Americans are not one of them.
- On the US side, naturalising abroad does not end US citizenship on its own. The State Department presumes you meant to keep it.
- Spaniards who become American keep Spanish nationality only if they act within three years, for example with a declaration at a consulate. Naturalising in Spain usually takes 10 years of living there.
Can you have Spanish and US citizenship at the same time?
Yes, but it depends on how you become Spanish. On the US side, USA.gov says you do not have to choose one nationality, and that a US citizen may naturalise in another country without risking US citizenship.
Spain's rules are in its Civil Code, articles 17 to 26. We read them on the BOE, Spain's official gazette, on 26 October 2026. Three cases matter for Americans:
- Spanish from birth. Article 17 says a child of a Spanish father or mother is Spanish by origin.
- Spanish later. People who become Spanish by residence, by option or by a special grant must meet Article 23. One of its conditions is a declaration that you renounce your old nationality.
- Spaniards who become American. Article 24 says they lose Spanish nationality after three years, unless they declare that they want to keep it.
So someone Spanish from birth can usually hold both. For someone who naturalises, the answer turns on what each country does with that declaration.
Do Americans have to give up US citizenship to become Spanish?
Spain asks you to declare that you renounce it, if you naturalise. The US does not treat naturalising abroad as giving up US citizenship on its own. Article 23 makes three things a condition for the new nationality to be valid:
- An oath or promise. Loyalty to the King, and obedience to the Constitution and the laws.
- A declaration. That you renounce your previous nationality.
- Registration. The new nationality is entered in the Spanish Civil Registry.
Article 21 says a grant lapses if you do not appear to do these within 180 days of being told about it.
What the declaration does to your US citizenship is a question for the US. The State Department's manual, 7 FAM 080, says US citizens who naturalise in a foreign country do not automatically lose US citizenship, and that their intent to keep it is presumed. It also says that someone who later tells a US consular officer they meant to give it up will lose it. USA.gov says a formal renunciation is an oath you sign at a US embassy or consulate.
Spain has a rule for after, too. Article 25 says someone who is Spanish but not by origin loses Spanish nationality if, for three years, they use only the nationality they declared they renounced.
Who is exempt from giving up their old nationality?
Nationals of a short list of countries, and Sephardic Jews of Spanish origin. Article 23 names them, and the countries are the ones in Article 24: the Ibero-American countries, Andorra, the Philippines, Equatorial Guinea and Portugal. The United States is not on the list.
People who are Spanish from birth are outside Article 23 altogether. It covers only nationality gained later, by option, by a special grant or by residence. Here is how each route works for an American:
| Route | Who it is for | Declare you renounce? |
|---|---|---|
| By origin (Article 17) | A child of a Spanish father or mother | No |
| By option (Article 20) | For example, a child of a parent who was Spanish by origin and born in Spain | Yes, unless exempt |
| By residence (Articles 21 and 22) | People who have lived in Spain for the time the law sets | Yes, unless exempt |
| By special grant (Article 21) | People with exceptional circumstances, by royal decree | Yes, unless exempt |
What does the US say about it?
That you may hold both. USA.gov says dual citizens owe allegiance to both countries, must use a US passport to enter and leave the US, and do not have to choose one nationality over the other.
The State Department's manual adds some detail:
- The law. US nationality law does not directly address dual nationality. The Supreme Court has called it "a status long recognized in the law".
- The policy. The US government accepts dual nationality but does not encourage it, because of the problems it can cause.
- Abroad. When you are in your other country of nationality, that country has the main claim on you. So in Spain, US help for a dual citizen may be limited.
USA.gov also lists the ways a US citizen can lose citizenship. One is applying for citizenship in another country with the intent of giving up US citizenship. The full US picture, including tax, is in dual citizenship for Americans, explained.
Can Spaniards who become American keep Spanish nationality?
Yes, if they act within three years. Article 24 says a Spaniard who lives abroad and takes another nationality by choice loses Spanish nationality three years after that. They avoid it by declaring, inside those three years, that they want to keep it. Taking the nationality of an Ibero-American country, Andorra, the Philippines, Equatorial Guinea or Portugal does not count against a Spaniard by origin. The US is not on that list.
The Spanish consulate in Miami explains the two ways to do it:
- A declaration. Made in person before the consular Civil Registry.
- An act. Something that uses your rights or meets your duties as a Spaniard. The consulate decides whether it counts.
Children born in the US can be caught by the same clock. Article 24 says a Spaniard born and living abroad, whose Spanish parent was also born abroad, loses Spanish nationality if the country they live in makes them its national, unless they declare they want to keep it. They have until three years after they turn 18.
Someone who has lost it can get it back under Article 26. They live legally in Spain, declare to the Civil Registry that they want it back, and register it. The rule on living in Spain does not apply to emigrants or their children.
How long until you can naturalise in Spain?
Ten years of living there, for most people, Americans included. Article 22 sets shorter times for some:
| Who | Years living in Spain |
|---|---|
| Most people, including Americans | 10 |
| Refugees | 5 |
| Nationals by origin of an Ibero-American country, Andorra, the Philippines, Equatorial Guinea or Portugal, and Sephardic Jews | 2 |
| Married to a Spaniard for a year, and not separated | 1 |
| Born abroad to a parent or grandparent who was Spanish by origin | 1 |
| Born in Spain | 1 |
The law lists a few more one-year cases, such as the widow or widower of a Spaniard. The time must be legal, without a break and right before you apply. You also show good civic conduct and that you have settled into Spanish society. The Minister of Justice grants it, and can refuse it for reasons of public order or national interest.
To start the clock, you first need a right to live in Spain. Remote workers can look at the Spain digital nomad visa, which asks for at least twice Spain's monthly minimum wage. People living on a pension or their own money can look at the Spain non-working residence visa, which asks for EUR 2,400 a month in 2026, or a year of that in savings, and does not allow work. Spain's investor visa closed on 3 April 2025, so it is no longer a route.
Two passports also mean two lists of places you can visit without a visa. Compare where a Spanish passport gets you in with where a US passport gets you in.