Conflicting nationality laws are one of many causes of statelessness.
Nationality is usually acquired through one of two modes, although many nations recognize both modes today:
Jus soli ("right of the soil") denotes a regime by which nationality is acquired through birth on the territory of the state. This is common in the Americas.
Jus sanguinis ("right of blood") is a regime by which nationality is acquired through descent, usually from a parent who is a national. Almost all states in Europe, Asia, Africa, and Oceania grant citizenship at birth based upon the principle of jus sanguinis.
A person who does not have either parent eligible to pass citizenship by jus sanguinis can be stateless at birth if born in a state which does not recognize jus soli.
For instance, a child born outside Canada to two Canadian parents, who were also born outside Canada to Canadian parents, would not be a Canadian citizen, since jus sanguinis is only recognized for the first generation in Canada.
If the child were born in India and neither parent had Indian citizenship, then the child would be stateless since India only confers citizenship to children born to at least one Indian parent.
Discrimination by Race, Religion, or Gender:
In most large-scale statelessness situations, statelessness is a result of discrimination.
Many states define their body of citizens based on ethnicity, leading to the exclusion of large groups.
This violates international laws against discrimination.
The United Nations Committee on the Elimination of Racial Discrimination stated on 1 October 2014 that the "deprivation of citizenship on the basis of race, color, descent, or national or ethnic origin is a breach of States’ obligations to ensure non-discriminatory enjoyment of the right to nationality.
Although many states allow the acquisition of nationality through parental descent irrespective of where the child is born, some do not allow female citizens to confer nationality to their children.
This can result in statelessness when the father is stateless, unknown, or otherwise unable to confer nationality.
People may also become stateless as a result of administrative and practical problems, especially when they are from a group whose nationality is questioned. Individuals might be entitled to citizenship but unable to undertake the necessary procedural steps. They may be required to pay excessive fees for documentation proving nationality, to provide documentation that is not available to them, or to meet unrealistic deadlines; or they may face geographic or literacy barriers.
In rare cases, individuals may become stateless upon renouncing their citizenship. Many states do not allow citizens to renounce their nationality unless they acquire another. However, consular officials are unlikely to be familiar with the citizenship laws of all countries, so there may still be situations where renunciation leads to effective statelessness.