Mercenaries group dealing with the mercenary provision reported that

Mercenaries receive no mention in any of the four Geneva Conventions of 1949. The first mainstream international humanitarian law instrument to deal specifically with mercenaries was the 1977 Additional Protocol I thereto. It applies exclusively to international armed conflicts and fewer states are party to it than to the Geneva Conventions of 1949. Nevertheless, the ICRC considers Article 47 of Additional Protocol I as reflecting customary international humanitarian law.

This mercenary provision was first proposed in 1976 by the Nigerian delegation to the Diplomatic Conference, albeit in slightly different terms. In 1977, following significant debate and consideration of the issue by a working group, the article was adopted by consensus. Many delegations stated that they supported the inclusion of the provision, ”in the spirit of compromise”.  Indeed, the working group dealing with the mercenary provision reported that ”It should not be thought that all delegates were fully satisfied with the final text.” Article 47.1 of Additional Protocol I provides that individuals who are found to be mercenaries are to be deprived of the rights of combatant or prisoner of-war status.

Article 47.2 defines a mercenary as any person who:Is specially recruited locally or abroad in order to fight in an armed conflict;Does, in fact, take a direct part in the hostilities;Is motivated to take part in the hostilities essentially by the desire for private gain and, in fact, is promised by or on behalf of a Party to the conflict material compensation substantially in excess of that promised or paid to combatants of similar rank and functions in the armed forces of that Party;Is neither a national of a Party to the conflict nor a resident of territory controlled by a Party to the conflict;Is not a member of the armed forces of a Party to the conflict;Has not been sent by a State which is not a Party to the conflict on official duty as a member of its armed forces;International Convention against the Recruitment, Use, Financing and Training of Mercenaries, is a 2001 United Nations treaty that prohibits the recruitment, training, use, and financing of mercenaries. At the 72nd plenary meeting on 4 December 1989, the United Nations General Assembly concluded the convention as its resolution 44/34. The convention entered into force on 20 October 2001 and has been ratified by 35 states.Countries with large militaries that have not ratified the convention include China, France, India, Japan, Russia, the United Kingdom, and the United States