Becoming a Spanish citizen currently requires giving up your nationality and passport unless you are from a nation recognized as a former colony of Spain. (Although if, for example, you are British, the UK authorities allow dual nationality so will still consider you a British subject).
If you are considering Spanish citizenship, here's how to do it.
Nationality via residence
This form of requiring nationality requires the person concerned to have been a legal resident of Spain for an uninterrupted period of ten years immediately prior to the application.
An application for Spanish citizenship must be made to the Ministry of Justice, who can refuse it on grounds of public order or national interest.
To apply for Spanish nationality you require your birth certificate, marriage certificate (if applicable), a certificate of good conduct from the police in your country of origin, all of which must be officially translated into Spanish.
Once you have been approved, you have to swear your loyalty to the King and promise to obey the Spanish constitution and laws.
You will also have to present certificates from the Cervantes Institute proving you have passed a language test (DELE) and a cultural knowledge multiple choice exam (CCSE). Of which more later.
Photo: Alagich Katya/Flickr.
One way to drastically shorten the waiting time to gain Spanish nationality is to be married to a Spaniard.
If you have been married to a Spaniard for at least one year, you can apply for Spanish nationality, also via the Ministry of Justice.
You have to still be married to a Spaniard upon application, no separated or divorced people need apply.
Widows and widowers of Spaniards can also immediately apply for Spanish citizenship.
You can apply for Spanish nationality if one or both of your parents or grandparents is Spanish, even if they were born outside of Spain.
Conversely you can also apply for citizenship if you were born in Spain to foreign parents.
Again, you need to apply through the Justice ministry.
If you happen to be able to prove that you have Sephardic Jewish ancestry, then you can apply for Spanish citizenship, even if you are not a resident in Spain. The law approved in 2015 is open to Jewish and non-Jewish people of Sephardic origin, provided that they can prove their Sephardic origin and a special connection with Spain.
More details on how to apply can be found here.
Pass the citizenship test
Since October 2015, those applying for citizenship in Spain are required to pass a test to prove their Spanish language skills and how well they have integrated into Spain - an issue that has caused its fair share of controversy.
Take our test to see if you know enough to gain Spanish citizenship.
All official information on applying for Spanish citizenship can be found on Spain's Justice Ministry website.
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