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.