GLOBALCIT has published a new study on “Citizenship acquisition by immigrants and their descendants: an international legal comparison”. This report, commissioned by the State Secretariat for Migration (SEM) in Switzerland, provides a comparative study of conditions and procedures for the acquisition of citizenship by foreign immigrants (first generation) and their descendants (second and third generation) in Europe.
The background for this commissioned study is a request from the Commission of the Federal Chamber of the Swiss Parliament (Ständerat) to the Swiss government (Bundesrat) to find out why citizenship acquisition numbers among the second generation of immigrant origin are so low. In addition to studies on naturalisation statistics, the Swiss government requested a comparative study to place the existing Swiss regulations on citizenship acquisition in an international perspective. These studies also served as input for a response by the Swiss government to a popular petition called the “Democracy Initiative”, submitted in November 2024 with 104,569 signatures for a “modern citizenship law”. It proposed that the conditions for naturalisation, which currently vary strongly across Swiss cantons and municipalities, should be regulated under federal law. Substantively, the petition proposed that foreign nationals should be entitled to acquire Swiss citizenship after 5 years of legal residence, provided they had not been convicted to a longer prison sentence and had basic knowledge of a national language.
In November 2025, the Bundesrat recommended to Parliament to reject the Democracy Initiative proposal, arguing in a press release, that the three-tier system of naturalisation in Switzerland – in which federal law determines only minimum conditions to which cantons and municipalities can add others – has withstood the test of time and should be maintained. However, referring to external expert opinion and analysis, the Bundesrat recommended that the cantons should examine possibilities for facilitating and harmonising naturalisation conditions. Since the analyses had found that naturalisation interviews in some cantons are currently not recorded, the government also recommended a duty to provide official records of such interviews in order to enhance legal security in the naturalisation process.
The focus of the GLOBALCIT study is on 11 selected European countries: Austria, Belgium, Denmark, France, Germany, Italy, Latvia, the Netherlands, Portugal, Sweden, and the United Kingdom. This study includes an in-depth comparison of the conditions and procedures for residence-based naturalisation, for citizenship acquisition by children and young adults, and for citizenship acquisition based on birth in the country. The study also covers counselling and information provisions. To ensure a systematic and comprehensive comparison of the requirements and procedures for citizenship acquisition across countries, the report draws on the internationally recognised comparative framework of the GLOBALCIT Citizenship Law Dataset.
The study includes detailed country reports that interpret the operation of citizenship laws within legal systems and demographic contexts. The findings from these country reports are summarised in a comparative synthesis, highlighting the variation in conditions and procedures for citizenship acquisition. Finally, the report provides a broader contextualisation of these findings by drawing on the data from the GLOBALCIT Citizenship Law Dataset on the conditions for citizenship acquisition in 31 European countries (all 27 EU member states, plus Switzerland, Iceland, Norway, and the UK).
The report highlights that naturalisation conditions vary across European states regarding length, permissible interruptions, and the requirement to hold a particular type of residence permit. The most common residency requirement is five years, but several states require longer residence, up to ten years. Fast-tracked naturalisation for special groups exists across Europe. Various states maintain lower residence requirements for spouses/partners of citizens, refugees and/or stateless persons, and citizens of specific origin (e.g., EU or Nordic Union citizens).
In all eleven states examined, a legal residence status is obligatory at the time of application for naturalisation. The number and types of permissible interruptions of a required residence period vary substantively across states. Some states calculate a percentage or number of days spent abroad, while others calculate residency more subjectively by determining the centre of life or sufficient ties.
Restrictions on dual or multiple citizenship are increasingly uncommon in Europe. In the limited number of European states that still require renunciation of another citizenship as a condition for naturalisation, there are significant exceptions (e.g., for spouses/partners of citizens or citizens of origin countries with strong economic or political ties to the state).
Most states require applicants for naturalisation to demonstrate language proficiency, typically at an intermediate level and tested through a language exam. Citizenship knowledge tests are somewhat less common, but still widely applied. There is some variation between states on whether the knowledge test is conducted during an in-person interview or in written form.
The procedure for ordinary naturalisation is typically discretionary. This means that the fulfilment of all naturalisation criteria is necessary, but that it does not legally guarantee the acquisition of citizenship. Some states provide guidance to the administrators on how to interpret the law. A few states provide an entitlement to naturalise if the applicant fulfils all the requirements, or do so for certain categories of applicants when all criteria are fulfilled, such as for spouses or minor children. In such cases, there is little discretion for authorities.
Applicants must provide documentation to support their application for naturalisation. This, most often, includes a valid identification (such as a copy or original of a passport), birth certificates, and proof of residence, or a copy of a residence permit. These documents need to be translated into the language of the host state (and in some cases certified by the home state).
In the eleven states included in the study, once an application has been submitted, the processing time varies between 6 to 48 months among states. Some states guarantee a specific timeframe within which they will reach a decision. After a naturalisation application has been accepted, some countries have a further requirement that the applicants participate in a citizenship ceremony and take a pledge/oath of allegiance.
In almost all countries covered in the report, there is a possibility of appealing a negative decision. There is variation among the states on how the appeals are managed and on who manages them. Appeals may go back to the competent authority, be directed to a higher authority, or be sent to the courts.
All states require naturalisation applicants to pay a fee. The fees vary substantially from around 100 euros to well over 2000 euros. This basic fee does not include other costs incurred by the applicant, such as language courses, collecting, or translating documents. Most states provide reduced application fees for minors, spouses, refugees, and stateless persons.
There are a few states that provide targeted information or counselling services about the conditions under which citizenship can be acquired beyond the information provided on governmental websites. Exceptions exist where, as a part of general integration policies, there are measures at different levels of government to provide information on the conditions for acquiring citizenship. These include, for example, information portals and websites, information events and workshops, advisory services that specialise in supporting immigrants and citizenship candidates, brochures and information materials. Some states provide a free info phone line, an online space for questions, or information days that explain the naturalisation process and procedures. Other states have created local migrant support centres. Larger municipalities sometimes organise local naturalisation campaigns. These provide support with information and counselling on access to citizenship and may offer free legal advice services at the local level.
Beyond residence-based naturalisation for first-generation immigrants, many European states provide facilitated pathways to citizenship for the children of immigrants. Different pathways exist for children who arrive in a country at a young age and for those who are born in a country. In no European country is citizenship acquired based on birth in the country without any other conditions. However, several states offer citizenship pathways to persons born in the country if neither parent is a citizen. In those cases, the acquisition of citizenship is conditional on the residence status and length of residence in the country of the foreign parent. If one of the parents is born in the country, this may also entitle the child born in the country to citizenship at birth. In some states, persons born in the country can acquire citizenship after birth at or before the age of majority under certain conditions.
Often, but not always, states provide special acquisition procedures as a part of these facilitated pathways to citizenship based on birth in the country or childhood residence/schooling. These procedures typically involve submitting an oral or written declaration (by the person or by his/her legal representative) addressed to the relevant public authorities. In some countries, such a declaration is a unilateral act by the person concerned. Citizenship is then acquired immediately and does not depend on a discretionary decision by the authorities.
Where citizenship can be acquired through a declaration, in most cases, documentation requirements are less rigorous than those for residence-based naturalisation. Generally, the relevant authority is the same that also handles residence-based naturalisation. Overall, the process of acquiring citizenship by declaration is faster than residence-based naturalisation.
Appeal procedures to declaration decisions are generally the same as for residence-based naturalisation. In most cases, fees for registration are significantly lower than for residence-based naturalisation.
More information: Citizenship acquisition by immigrants and their descendants: an international legal comparison