Lex solis

Lex solis (the "law of the earth" or "territory", also called jus solis) refers to the acquisition of nationality or citizenship of a state by birth on the territory of the state. The law of most states provide for acquisition of nationality by lex solis, and it is the most common means of acquiring nationality.

Traditionally the only exception to lex solis has been that the child was born to a parent in the diplomatic or consular service of another state, on a mission to the state in question; however increasingly countries are restricting lex solis by requiring that at least one of the child's parents be a national of the state in question at the child's birth, or a legal permanent resident of the territory of the state in question at the child's birth, or that the child be a foundling found on the territory of the state in question.

Compare lex sanguinis.