To become a citizen of Luxembourg, most foreign adults naturalize after five years of legal residence, pass the Luxembourgish language test (Sproochentest), and complete the “Vivre ensemble au Grand-Duché de Luxembourg” civic course. Faster option procedures exist for spouses of Luxembourgers, long-term residents, people schooled in Luxembourg, and descendants of Luxembourgish nationals, and children often acquire citizenship automatically. Luxembourg has allowed dual citizenship without restriction since January 1, 2009, so you do not have to give up your current nationality to naturalize.
Requirements Every Applicant Must Meet
Before looking at any specific route, three baseline conditions apply to nearly every adult applicant.
Age and Good Repute
You must be at least 18. The only exception is children born in Luxembourg, who can apply from age 12 through the option procedure.
Luxembourg also requires a “condition of good repute.” Your application will be refused if you have received, in Luxembourg or abroad, a criminal or custodial sentence of 12 months or more, or a suspended sentence of 24 months or more. The conviction must have been definitively served less than 15 years before your application, and for foreign convictions, the underlying conduct must also be a criminal offense under Luxembourg law.
The Luxembourgish Language Test
The Sproochentest Lëtzebuergesch tests oral expression at the A2 level of the European CEFR framework and oral comprehension at the B1 level. Passing the A2 oral expression portion alone is enough to pass the whole test, and an insufficient A2 score can be compensated by a higher B1 comprehension score. Registration costs €75, which you can apply to have reimbursed by the state.
Civic Knowledge Course
You must either complete the “Vivre ensemble au Grand-Duché de Luxembourg” course or pass the equivalent exam. Registration for both the course and the exam is free.
Naturalization: The Standard Five-Year Path
Naturalization is the most common route. You need at least five years of legal residence in Luxembourg, with the final year immediately before the application being uninterrupted, plus the language test and civic course. The naturalization procedure itself is free of charge, although you will pay for supporting documents such as criminal record certificates and civil status records from foreign authorities.
Faster Routes: The Option Procedures
Option is a lighter procedure recorded directly by the civil registrar in your commune, rather than going through a full Ministry of Justice review. Several categories qualify.
Marriage to a Luxembourgish Citizen
If you are married to a Luxembourgish national and live in Luxembourg, you can apply immediately. There is no waiting period. You still need the language test and the civic course.
The three-year marriage waiting period that many people associate with this pathway only applies if you live outside Luxembourg. Even that waiting period is waived if your spouse holds a position assigned by a Luxembourg public authority or an international organization. This resident/non-resident distinction is one of the most commonly misunderstood rules in Luxembourg nationality law.
Seven Years of Schooling in Luxembourg
Adults who completed at least seven years of public schooling in Luxembourg can apply by option with 12 months of legal residence immediately before the application, plus the standard language and civic requirements.
Twenty Years of Residency
If you have lived legally in Luxembourg for at least 20 years, you qualify for a simplified option. Instead of the Sproochentest and the Vivre ensemble exam, you only need to attend 24 hours of Luxembourgish language classes. Each course organizer sets its own fee for these classes.
Refugees, Stateless Persons, and Subsidiary Protection Holders
People with refugee status, stateless person status, or subsidiary protection status can apply by option after five years of legal residence, including 12 months of continuous residence immediately before the application. The language test and civic course apply.
Descent From a Luxembourgish Parent or Grandparent
Adults with a parent or grandparent who is or was a Luxembourgish national can apply by option.
Birth in Luxembourg (Ages 12 to 17)
Children born in Luxembourg to non-Luxembourgish parents can apply from age 12 if they have lived legally in the country for at least five consecutive years before the application. For children born after July 2013, one non-Luxembourgish parent must also have legally resided in Luxembourg for at least 12 months before the child’s birth.
When Children Become Citizens Automatically
Children often do not need to apply at all. Luxembourgish nationality is acquired by operation of law in three situations:
- Any child born to a parent who is Luxembourgish at the time of birth, or when the parent-child relationship is later established, is automatically Luxembourgish.
- If one of your parents acquires Luxembourgish nationality through naturalization, option, or reclamation while you are still a minor, you become Luxembourgish as well.
- Minor children adopted by a Luxembourgish national automatically receive citizenship.
Separately, children born in Luxembourg to foreign nationals automatically acquire citizenship at 18, provided they resided in Luxembourg for at least five consecutive years before that birthday and one parent lived in Luxembourg for at least 12 months before the birth.
Ancestry Reclamation Has Closed
Luxembourg offered a special reclamation procedure for direct descendants of an ancestor who held Luxembourgish nationality on January 1, 1900. That window has closed. Applicants were required to request certification from the Ministry of Justice by December 31, 2018, and to sign the reclamation declaration before a civil registrar by December 31, 2025. If you missed either deadline, this route is no longer available. Adults with a Luxembourgish parent or grandparent may still apply through the option procedure described above.
How to Apply
You submit your application in person to the civil registrar (officier de l’état civil) in your commune of residence. If you live outside Luxembourg, you submit to the civil registrar of the City of Luxembourg. There is no filing fee.
For naturalization, the civil registrar verifies your file and forwards it to the Ministry of Justice, which must decide within a maximum of eight months. Incomplete files stall the timeline: if documents are missing, the application sits pending until you provide them. Option declarations are faster because they are recorded directly by the civil registrar, though the Ministry can cancel a declaration within four months if it finds legal violations or fraud.
Documents You Will Need
For naturalization, expect to file all of the following:
- A full copy of your birth certificate, plus those of any children under 18.
- A valid passport copy, plus copies for children under 18. Another identity or travel document may substitute if you have no passport.
- The biographical questionnaire (notice biographique), completed honestly, signed, and dated.
- Criminal record certificates from every country where you hold or held citizenship, and from every country where you lived as an adult during the 15 years before your application. The civil registrar separately requests your Luxembourg criminal record (record no. 2) from the public prosecutor’s office, but only with your written authorization; refusing to authorize this will stop your application.
- Your Sproochentest Lëtzebuergesch pass certificate.
- Proof that you completed the Vivre ensemble course or passed the exam.
Documents not drafted in French, German, English, or Luxembourgish must be submitted with a translation by a sworn translator or a foreign public authority. Documents from outside the EU will typically need an apostille; Luxembourg has been a member of the Hague Apostille Convention since 1979. The official Guichet.lu portal keeps a current checklist for each pathway.
If Your Application Is Refused
You can appeal a refusal to the Minister of Justice within one month of being notified. If the Minister also rejects the appeal, you can challenge that decision before the administrative tribunal, where the appeal must be filed by a court lawyer (avocat à la Cour).
Fraud carries consequences well beyond a denial. If the Ministry determines you made false statements, concealed important information, or acted fraudulently, cancellation of your application comes with a 15-year ban on initiating any naturalization, option, or reclamation procedure.
What Changes Once You Are a Citizen
Voting in legislative elections is compulsory for registered voters who are Luxembourg citizens, at least 18 years old, and living in the country. Unjustified failure to vote is punishable by a fine, and repeat offenses carry increased penalties. If you cannot vote, you must explain your absence to the local State Prosecutor with supporting documentation. Voters over 75 and those living in a different municipality from their assigned polling station are exempt.
One boundary to flag for American applicants: the United States taxes its citizens based on citizenship rather than residence, so acquiring Luxembourgish nationality does not end your U.S. tax filing obligations. A bilateral U.S.–Luxembourg tax treaty signed in 1996 sets rules on which country taxes which types of income and caps rates on dividends, interest, and royalties, and most dual citizens rely on the Foreign Earned Income Exclusion or the Foreign Tax Credit to avoid actual double taxation. You will still need to file U.S. returns every year, and if your combined foreign financial accounts exceed $10,000 at any point during the year, you must also file a Report of Foreign Bank and Financial Accounts (FBAR).