T H E G L O B A L S TAT E O F C I T I Z E N S H I P In 33 countries, whether or not a child born in the country becomes a citizen will depend on additional requirements. A child born to foreign parents may become a citizen if their parent is born in the territory or fulfils a certain residence requirement. For example, a child born in Germany is automatically a German citizen if one of the parents has legal residence there for five years before the child’s birth. For countries that mainly rely on descent-based transmission of citizenship, this additional form of territorial birthright citizenship ensures that the children of immigrants are also included in the nation. Interestingly, in Germany, the residence requirement for parents was lowered from eight to five years before the child’s birth, as part of a broad ‘modernisation’ of German citizenship law in 2024. In section 3 of this report, we discuss more extensively how countries have adjusted their citizenship laws (or failed to do so) to the phenomenon of immigration. 1.4 DIFFERENT PATHWAYS TO CITIZENSHIP Beyond birthright All states specify the grounds for birthright citizenship in their laws, but they do so in different ways, mixing the principles of descent and territory. Beyond birthright, in most countries, there are other pathways to become a citizen. In this section, we map these pathways, as well as the ways to lose citizenship. Descent (birth abroad) 191 Residence-based acquisition 177 Marriage 171 Reaquisition 160 Descent (birth in country) 158 Foundlings 139 Child coaquisition 130 Special achievements 129 Adoption 122 Otherwise stateless (birth in country) 93 Birth in country 82 Birth in country (acq after birth) 60 Stateless 60 Spousal coacquisition 53 Cultural affinity 52 Citizen of specific country 50 Establishment of parentage 48 Refugees 42 Public service 40 No. of countries Frequency of 20 selected acquisition grounds across 191 countries | 2024 Source: GLOBALCIT Citizenship Law Dataset, v3, selected modes Finally, in a smaller group of countries, the law opens up a pathway to citizenship for economic investors, something that is frequently considered a controversial ‘sale of passports’. Ways to acquire citizenship When a person becomes a citizen of a country other than by birth, this is what we understand by ‘naturalisation’. Ordinary immigrants living in a country other than the one in which they were born can naturalise after some period of residence in most, but not all, countries. Though, as we discuss in further detail in section 3, the requirements vary greatly country-by-country. Those who are married to a citizen often also benefit from facilitated access to citizenship, in terms of shorter residence periods or fewer requirements. However, several countries discriminate on the basis of gender, with facilitated citizenship for wives but not husbands of citizens. We discuss discriminatory rules like these in section 2 of the report. In the Americas, where countries apply territorial birthright to children born in their territory without any further conditions nearly universally, there is less need to formulate special acquisition grounds. For example, in Uruguay, one can only acquire citizenship by being born in the country or abroad to a Uruguayan. In Europe, by contrast, being born in the territory of a country typically does not entail an unconditional right to citizenship; at best, this will depend on the residence status or place of birth of one’s parents. The laws of European countries, therefore, often include compensatory clauses for a lack of territorial birthright that ensure that the children of migrants have facilitated access to citizenship. For example, children as young as three years old who have lived in Sweden for that period can become Swedish, even if they were not born there. This is considerably easier than in Denmark, where one can only naturalise at the age of 18, if they have lived there since their 15th birthday and had their education in Denmark. Beyond these general rules, some states facilitate citizenship on ‘special’ grounds, such as the acquisition of citizenship by former citizens (‘reacquisition’), adopted children, refugees, stateless persons, as well as persons considered to have made an extraordinary contribution to the country, for example in sports, the arts or science (‘special achievements’). 8