Option of nationality

In international law, the option of nationality or right of option refers to the right of an individual (optant) to choose their nationality when the sovereignty over their territory is transferred from one state to another. By choosing a nationality the optants exclude themselves from an ex lege determination of nationality, the automatic nationality change, allegiance to the new ruler, and potential forcing of new religion upon them. The provision was often included in peace treaties, allowing a population to maintain its original citizenship, typically on the condition of emigration from the ceded territory within a specified period. Some legal scholars view the right to choose one's nationality as an inherent component of the principle of self-determination.

There are three primary forms of the option of nationality:

• Positive option, by which individuals are given nationality of the state where they were born
• Negative option, which forces optants with nationalities obtained through both jus sanguinis (right of blood) and jus soli (right of the soil) to abandon their jus soli nationality
• Confirmative option, which is the most common form, requiring an individual to confirm their original nationality by emigrating from the ceded territory within a specified time frame.

The 1954 United Nations Survey of the problem of multiple nationality states that it is "widely held that, in case of change of sovereignty over a territory by annexation, or its voluntary cession by one State to another, the annexing State is obliged to grant its nationality to the inhabitants of the territory concerned who were citizens of the ceding State, at least if they have, at the time of annexation, their permanent residence in the ceded territory. In most instances these questions are settled by treaty between the States concerned, which also frequently grant a right of option to the inhabitants."