How is dual citizenship assessed under Belgian law?

Is dual citizenship permitted under Belgian law? What happens when a Belgian citizen acquires another citizenship? Can a foreigner retain their previous citizenship when acquiring Belgian citizenship? How do the 28-year-old rule and the loss of citizenship work? This comprehensive guide examines the Belgian dual citizenship regime in detail, based on current official sources. (justice.belgium.be)

In Belgian law, dual citizenship is no longer an exceptional situation; on the contrary, it is a legally recognized status frequently encountered both by birth and through subsequent acquisition of citizenship. However, the statement "Belgium allows dual citizenship" is not sufficient on its own. What is truly important is under what conditions Belgium accepts, from what date it made it permissible, what happens if Belgians acquire another citizenship, whether foreigners can retain their previous citizenship when acquiring Belgian citizenship, and the risk of protection, which arises around the age of 28, works, especially for some Belgians born abroad. Official Belgian sources clearly regulate this area. While the Belgian Justice Service accepts dual citizenship for adults, Foreign Ministry sources state that Belgian authorities, as a rule, do not require individuals who acquire Belgian citizenship to renounce their previous citizenship. (justice.belgium.be)

In Belgian law, this issue is particularly important in three different scenarios. The first scenario is when a person who is already a Belgian citizen subsequently acquires the citizenship of another state . The second scenario is when a person who is a citizen of another state acquires Belgian citizenship . The third scenario is when a child acquires multiple citizenships simultaneously at birth . The legal consequences of these three scenarios are not the same. Furthermore, the fact that Belgium allows dual citizenship does not mean that the same flexibility exists in the law of the person's other citizenship. Indeed, official Belgian sources specifically emphasize that whether a foreigner can retain their previous citizenship if they acquire Belgian citizenship depends on the law of their state of origin . ( justice.belgium.be )

Therefore, the correct answer to the question "Is dual citizenship allowed in Belgium?" is: Yes, Belgian law currently recognizes voluntary multiple citizenship; however, the specific consequences vary depending on how and when a person acquired citizenship and what other relevant state laws dictate. These distinctions are particularly critical for families crossing borders, investors wishing to settle in Belgium, individuals married to Belgian citizens, Belgian children born abroad, and Belgians who subsequently wish to acquire another citizenship. (justice.belgium.be)

1. How is the concept of dual citizenship understood in Belgium?

According to the Belgian Justice Service, dual citizenship, or multiple citizenship, means that a person simultaneously holds Belgian citizenship and the citizenship of one or more other countries. The official classification gives three main examples: children who automatically acquire two citizenships at birth; Belgians who acquire another citizenship in adulthood but retain their Belgian citizenship; and foreigners who acquire Belgian citizenship later in life and do not lose their previous citizenship. Thus, the Belgian system recognizes dual citizenship not merely as a condition limited to birth, but as a broad legal status encompassing acquired citizenship. (justice.belgium.be)

In Belgium, dual citizenship is not merely a theoretical status; it has direct consequences in terms of population registration, passports, identity cards, consular procedures, and the risk of losing citizenship. Official foreign affairs sources explicitly state that even if a person holds another citizenship, Belgian authorities always consider them Belgian. This statement shows that Belgium prioritizes Belgian citizenship in the eyes of its own authorities. Therefore, a person who is a Belgian citizen, even if they simultaneously hold another citizenship, is not treated as a "foreigner" by Belgium; municipal, identity card, and passport procedures are carried out on the basis of Belgian citizenship. (canada.diplomatie.belgium.be)

2. Since when has Belgium accepted voluntary dual citizenship?

Although the current liberal regime in Belgium appears to have existed for a long time, historically this area has developed gradually. According to the Justice Service's adult page, from June 9, 2007, Belgians retained their Belgian citizenship when they voluntarily acquired the citizenship of a state that is not a party to the Council of Europe's 1963 Convention on the Reduction of Multiple Citizenship. From April 28, 2008, the prohibition was completely lifted, and thus, acquiring another citizenship voluntarily no longer resulted in the loss of Belgian citizenship, even with respect to the listed states. Foreign Ministry sources summarize this more simply, since April 28, 2008, acquiring another citizenship voluntarily no longer invalidates Belgian citizenship . (justice.belgium.be)

This historical distinction remains important in practice, as the date on which a person acquired another citizenship can determine whether or not they have lost their Belgian citizenship. According to official sources, a Belgian citizen who voluntarily acquired another citizenship after the age of 18 and before June 9, 2007, may be considered to have lost their Belgian citizenship. Between June 9, 2007, and April 28, 2008 , the loss of citizenship was only possible in cases of voluntary acquisition of citizenship of certain specific countries. After April 28, 2008 , voluntary acquisition of another citizenship no longer invalidates Belgian citizenship. Therefore, in older cases, not only current law but also the regime in effect at the time of citizenship acquisition must be examined. ( justice.belgium.be )

3. What happens if a Belgian citizen later acquires another citizenship?

The fundamental rule of current Belgian law is clear: a Belgian citizen who voluntarily acquires the citizenship of another country does not lose their Belgian citizenship solely for that reason. Both the Justice Service and Foreign Office sources explicitly confirm this. Belgium no longer requires any additional permission, notification, or prior approval system in this regard. Indeed, the Justice Service states that the dual citizenship regime “requires no formalities,” and that no separate declaration to the municipality or foreign representation is necessary upon acquiring another citizenship. (justice.belgium.be)

However, this freedom does not mean that no legal attention is required. Firstly, while citizenship is preserved in Belgium, the law of the country where the person acquired their new citizenship must also be examined. Secondly, there is no automatic retroactive reinstatement in Belgian law. The Justice Service explicitly states that individuals who lost their Belgian citizenship due to acquiring another citizenship in the past do not automatically regain; they must make a separate declaration of reinstatement . Therefore, the approach of "dual citizenship is now permitted, so my Belgian citizenship that I lost in the past has automatically been restored" is not legally correct. (justice.belgium.be)

4. Can a foreigner retain their previous citizenship when acquiring Belgian citizenship?

Yes, as a rule, Belgian authorities do not require a foreigner to renounce their previous citizenship when acquiring Belgian citizenship. The Ministry of Foreign Affairs' "multiple nationalities" page explicitly states that if a person holding another citizenship acquires Belgian citizenship, Belgian authorities will not require them to relinquish their original citizenship. Similarly, the Justice Service states that if a foreigner acquires Belgian citizenship through declaration of citizenship or naturalization, they may hold dual citizenship if their own country's law permits it. (canada.diplomatie.belgium.be)

However, the most critical point here is this: just because Belgium doesn't force you to renounce your former citizenship doesn't necessarily mean it will be preserved. Official Belgian sources specifically emphasize that whether or not a former citizenship can be preserved the law of the individual 's country of origin. In other words, Belgium won't tell you to "give up first," but the other country whose citizenship you hold might say, "If you acquire Belgian citizenship, you will lose ours." Therefore, before applying for Belgian citizenship, it is necessary to examine not only Belgian law but also the foreign law relating to the individual's current citizenship. The most common mistake in practice is assuming that Belgium's permission for dual citizenship is sufficient on its own. (canada.diplomatie.belgium.be)

5. How can Belgian citizenship be acquired later in life, and what is its relationship to dual citizenship?

According to sources at the Ministry of Foreign Affairs, since January 1, 2013, Belgian citizenship for adults can essentially be acquired in two ways: declaration of citizenship and naturalization. The same source states that these methods are only who have their primary residence in Belgium and are registered in the population registers on the basis of legal residence . It is also explicitly stated that marriage alone does not confer Belgian citizenship; certain conditions, including residency in Belgium, must be met for citizenship through marriage. These rules are important in the debate over dual citizenship, as acquiring Belgian citizenship for a foreigner is often the result of a lengthy process involving residence, registration, and application categories. (canada.diplomatie.belgium.be)

Therefore, for a foreigner, dual citizenship usually occurs in the following model: the individual first establishes legal residence and primary domicile in Belgium, then acquires Belgian citizenship through declaration of citizenship or, exceptionally, naturalization, and retains their existing citizenship if the law of their home country permits. The Belgian authorities' approach at this stage is clear: the applicant is not asked to renounce their existing citizenship. However, the success of the application still depends on fulfilling the requirements for applying for Belgian citizenship; dual citizenship is not an automatic or unconditional right in Belgium, but merely a permitted outcome. (canada.diplomatie.belgium.be)

6. Dual citizenship by birth: what does Belgium say about this in terms of children?

In Belgian law, one of the classic forms of dual citizenship arises at birth. According to the Justice Service's page on children, a minor born to parents of different nationalities can acquire multiple citizenships at birth. Specifically, if one parent is Belgian and the child is born in Belgium, or if the Belgian parent was born in Belgium, the child can automatically acquire Belgian citizenship at birth. At the same time, they can also retain the citizenship of the other parent, to the extent permitted by that country's law. Therefore, in mixed marriages, dual citizenship often arises at birth, not later. (justice.belgium.be)

A very important principle adopted by Belgium here is that even if a child holds two or more citizenships, as long as they reside in Belgium, they are considered Belgian by the Belgian authorities and their population records are kept accordingly. This rule is similarly confirmed in foreign affairs sources for adults as well. Thus, Belgium bases its administrative and population law on Belgian citizenship. This approach is particularly important for family law, passport and registration processes. (justice.belgium.be)

7. How do Belgian authorities view dual citizenship?

Belgian foreign affairs sources use the phrase, "You will always be considered a Belgian citizen by the Belgian authorities." This is a very weighty statement. It means that a person with Belgian citizenship has Belgian citizenship as their primary legal identity in the eyes of the Belgian state. Therefore, even if a person simultaneously holds another passport, they are treated as Belgian by the Belgian municipality, the Belgian population registry, their Belgian identity card, and their Belgian passport. The same approach is seen on the Justice Service website for children; a child with two or more citizenships and living in Belgium is registered as Belgian in the population records. (canada.diplomatie.belgium.be)

This rule is particularly important in practice. Because some people believe they can use their second citizenship as an “alternative status” for all transactions in Belgium. However, Belgium's fundamental approach before its own authorities is different: if you are a Belgian citizen, Belgium primarily considers you Belgian. Therefore, under Belgian law, the existence of dual citizenship does not result in a “free choice between two equal citizenships” with respect to Belgium; at least from the perspective of the Belgian administration, Belgian citizenship remains the determining factor. (canada.diplomatie.belgium.be)

8. The most critical risk in dual citizenship: The 28-year-old rule

In Belgian law, the most overlooked aspect of dual citizenship of losing citizenship at age 28 . According to Foreign Ministry sources, if a person was born outside Belgium after January 1, 1967, holds one or more other citizenships, did not have their primary residence in Belgium between the ages of 18 and 28, did not work abroad for the Belgian state or a company/association established under Belgian law, and did not obtain a Belgian passport or identity card or make the necessary protection declaration between the ages of 18 and 28 , they may risk losing their Belgian citizenship at age 28. Official sources explain this mechanism in detail. (canada.diplomatie.belgium.be)

This regulation is particularly important for young people who are born with dual citizenship and have spent their entire lives abroad. Because the current freedom to voluntarily acquire another citizenship does not automatically guarantee the permanent retention of Belgian citizenship for everyone. Some individuals born outside Belgium and holding multiple citizenships may lose their citizenship if they do not legally demonstrate their connection to Belgium between the ages of 18 and 28. The Ministry of Foreign Affairs suggests two practical solutions: either a retention declaration must be made at a diplomatic mission between the ages of 18 and 28, or a Belgian passport or identity card must have been issued within the same age range. Therefore, for families, the most critical issue is often not acquiring citizenship, but retaining it at the right time. (canada.diplomatie.belgium.be)

9. Is it possible to voluntarily renounce Belgian citizenship?

Yes. According to the Justice Service, a Belgian citizen with dual citizenship can renounce their Belgian citizenship if they wish. This declaration can be made in the municipality where they have their main residence in Belgium, or, if they live abroad, at the competent Belgian embassy or consulate. The Foreign Ministry's general citizenship page also confirms that adults can renounce their Belgian citizenship with an explicit declaration of intent. (justice.belgium.be)

However, voluntary renunciation should be considered separately in the context of dual citizenship. If a person holds another citizenship in addition to Belgian citizenship, they are not obliged to retain Belgian citizenship; however, the effects of the decision to renounce citizenship on children, the status of the other citizenship, and the possibility of future reinstatement should be carefully examined. Foreign Ministry sources indicate that in certain cases, the loss of parental citizenship may have cumulative consequences for minor children, but this loss cannot be enforced if there is a risk of statelessness. Therefore, a decision to voluntarily renounce citizenship requires legal advice, not only in terms of individual but also family implications. (diplomatie.belgium.be)

10. The relationship between dual citizenship and the regaining of citizenship

While dual citizenship is permitted under Belgian law, it is not automatically restored for those who lost their citizenship in the past. The Justice Service explicitly states that Belgian citizenship lost under the old system does not automatically return after the reforms. The Ministry of Foreign Affairs also states that individuals who lost their Belgian citizenship in the past can regain it under certain conditions; as of January 1, 2013, this requires the individual to have their primary residence and legal domicile in Belgium. (justice.belgium.be)

This point is particularly important in older immigration and citizenship cases. A person may currently live under a legal system that allows for two or three citizenships; however, another citizenship obtained at the wrong time in the past may have led to the loss of Belgian citizenship. In such cases, the first question to be examined is "has it actually been lost?", and then "is there a way to regain it?". One of the most common mistakes regarding dual citizenship in Belgium is assuming that the current liberal regime applies retroactively. However, official sources state the exact opposite. (justice.belgium.be)

11. The most common mistakes in practice

The most common mistake in Belgian dual citizenship applications is focusing solely on Belgian law and neglecting the law of other states. However, Belgium explicitly states that whether a person can retain their previous citizenship depends on the law of their state of origin. A second common mistake is unaware of the age-28 protection regime. Young people born abroad and holding multiple citizenship may overlook the obligation to obtain a Belgian passport or identity card, or the declaration of protection. A third mistake is believing that Belgian citizenship, lost in the past when another citizenship was acquired, is automatically restored due to the current liberalization regime. Official sources implicitly rule out all three of these misconceptions. (canada.diplomatie.belgium.be)

Another mistake is confusing marriage with citizenship. Belgian law does not automatically grant citizenship. Marriage can, under certain conditions, pave the way for a citizenship application; however, it does not, by itself, result in citizenship or, consequently, dual citizenship. Similarly, the fact that Belgian authorities do not require renunciation of previous citizenship does not automatically mean that citizenship is acquired. The conditions for acquiring Belgian citizenship must first be met, and only then should the possibility of dual citizenship be discussed. (canada.diplomatie.belgium.be)

12. Conclusion

In Belgian law, dual citizenship is now a generally accepted status. Since April 28, 2008, Belgians who voluntarily acquire another citizenship do not lose their Belgian citizenship solely for that reason. Foreigners are not forced by Belgian authorities to renounce their previous citizenship when acquiring Belgian citizenship. Multiple citizenships can also be acquired by birth, particularly in mixed families. Furthermore, Belgian authorities always consider a person with dual citizenship as a Belgian citizen. (justice.belgium.be)

However, the dual citizenship regime in Belgium should not be understood as "completely free and risk-free." The historical context is important for acquisitions from the past; citizenship lost in the past does not automatically return; the law of the country of origin determines whether former citizenship can be preserved; for some multiple citizens born abroad, the obligation to obtain a protection declaration or passport/identity card arises around the age of 28. Therefore, Belgian dual citizenship cases, especially for families crossing borders and individuals planning investment/settlement, should be handled by considering both Belgian law and the law of other relevant states. A sound legal approach involves answering not only the question of "is it permitted?", but also how it was acquired, when it was acquired, which citizenships are held simultaneously, and what steps are necessary for their preservation . (justice.belgium.be)