A
private military corporation (
PMC),
private military firm (
PMF), or
private military or
security company, is a mercenary company or organisation providing armed or unarmed combat, combat support, security or security advisory services. PMCs refer to their staff as "security contractors" or "private military contractors". Private military companies refer to their business generally as the "private military industry" or "The Circuit". The hiring of
mercenaries is a common practice in the history of
armed conflict and prohibited in the modern age by the
United Nations Mercenary Convention; the
United Kingdom and
United States are not signatories to the convention, and the United States has rejected the UN's classification of PMCs as mercenaries.