Leaving No One Behind: Statelessness and the Sustainable Development Goals 2.1 The definition of a stateless person The legal definition of a stateless person is established by Article 1 of the 1954 Convention relating to the Status of Stateless Persons as “a person who is not considered as a national by any State under the operation of its law”.1 The UNHCR Handbook on Protection of Stateless Persons provides guidance on interpretation of this definition, noting that the determination of statelessness must be seen as a “mixed question of fact and law”.2 Those who cannot prove an entitlement to nationality under the relevant nationality laws, to the satisfaction of the competent authorities of any State to which they have a connection, must be regarded as stateless – even if the facts as narrated by the person concern appear to indicate that they have a claim to nationality. It is not the case that all those without a documented nationality are stateless. Especially in countries where national identification systems are weak, the nationality of some of those without documents may not be in doubt. In many contexts, moreover, stateless people do not lack identity documents; they are included in different registries and issued identity documents, but always as non-nationals.3 Most stateless people are living in the country of their birth and lifelong residence, what might be described as their “own country”.4 Only a minority are forcibly displaced or migrants. UNHCR refers to these two groups as stateless persons “in situ” or “in a migratory context”.5 In international law, nationality and citizenship are now used as synonyms for the status that gives a person certain rights and obligations in relation to a particular State. The terms can be used interchangeably in English. This study uses “citizenship” and “nationality” according to the terms used in the national context, and nationality at the international level (except where quoting documents using the term “citizenship”).6 2.2 How many people are stateless? At the end of 2024, UNHCR estimated that at least 4.4 million people worldwide were stateless.7 This number is based on information from 95 countries, often of limited statistical robustness, and UNHCR believes that it may have underestimated the total by many millions. The lack of even estimated statistics is partly due to a lack of deliberate efforts to perform the necessary surveys, but perhaps even more due to different interpretations of the definition of stateless person, especially in relation to people who lack identity documents and whose status as a national of any country is not certain. In 2023, the UN Statistical Commission adopted the International Recommendations on Statelessness Statistics (IROSS), drawing on the UNHCR Handbook on Protection of Stateless Persons and other guidance, which aim to improve the quality of the data.8 1. Article 1 of the 1954 Convention relating to the Status of Stateless Persons. 2. Handbook on protection of stateless persons under the 1954 Convention Relating to the Status of Stateless Persons” (Geneva: United Nations, 2014), www.refworld.org/policy/legalguidance/unhcr/2014/en/122573, Paras 23, 7. 3. For example, the Rohingya of Myanmar, see Natalie Brinham, “Looking beyond invisibility: Rohingyas’ dangerous encounters with papers and cards”, Tilburg Law Review 24, no. 2 (2019): 156, https://doi.org/10.5334/tilr.151. 4. UN Human Rights Committee, “General comment No. 27: Article 12 (Freedom of Movement)”, CCPR/C/21/Rev.1/Add.9 (Geneva, 2 November 1999), www.refworld.org/pdfid/45139c394.pdf. 5. “Handbook on protection of stateless persons”, paras. 1, 58–59; see also Caia Vlieks, “Contexts of Statelessness: The Concepts ‘Statelessness in Situ’and ‘Statelessness in the Migratory Context’”, in Understanding Statelessness, ed. Tendayi Bloom, Katherine Tonkiss, and Phillip Cole (Abingdon, Oxon; New York, NY: Routledge, 2017). 6. In many states (especially those of civil law tradition), the term “nationality” is used at both national and international level. Neither term has any connotation of ethnic or racial content in international law, but is simply the status that gives a person certain rights and obligations in relation to a particular State. 7. UNHCR, "Global Trends: forced displacement in 2024", June 2025 https://www.unhcr.org/global-trends. 8. UN Statistical Commission, “International recommendations on statelessness statistics (IROSS)” (United Nations, 20 January 2023), https://egrisstats. org/recommendations/international-recommendations-on-statelessness-statistics-iross/. Adopted by the Commission at its fifty-fourth Session, Decision 54/121. 15