undocumented

a person who has come to live permanently in a country without legal permission

travailleur sans papiers

a person who is employed in a country without the legal right to work there

une personne employée dans un pays sans avoir le droit légal d'y travailler

a person who moves to a foreign country, often for work, without official authorization

a term, often with legal or negative connotations, for a foreigner who has entered a country without authorization

the process of people moving into a country to live without the required legal documents