In espionage, agents under non-official cover (NOC) are operatives who assume covert roles in organizations without ties to the government for which they work. Such agents or operatives are typically abbreviated in espionage lingo as a NOC (pronounced "knock"). These agents are also known as "illegals". Non-official cover is contrasted with official cover, where an agent assumes a position at a seemingly benign department of their government, such as the diplomatic service. This provides the agent with official diplomatic immunity, thus protecting them from the steep punishments normally meted out to captured spies, instead usually resulting in the agent being declared persona non grata and ordered to leave the country.
Agents under non-official cover do not have this "safety net", and if captured or charged they are subject to severe criminal punishments, up to and including execution. Agents under non-official cover are also usually trained to deny any connection with their government, thus preserving plausible deniability, but also denying them any hope of diplomatic legal assistance or official acknowledgment of their service. Sometimes, entire front companies or strawman entities are established in order to provide false identities for agents.
An agent sent to spy on a foreign country might, for instance, work as a businessperson, a worker for a non-profit organization (such as a humanitarian group), or an academic. For example, the CIA's Ishmael Jones spent nearly two decades as a NOC.
Many of the agents memorialized without names or dates of service on the CIA Memorial Wall are assumed to have been killed or executed in a foreign country while serving as NOC agents. In nations with established and well-developed spy agencies, the majority of captured non-native NOC agents have, however, historically been repatriated through prisoner exchanges for other captured NOCs as a form of gentlemen's agreement.
Some countries have regulations regarding the use of non-official cover: the CIA, for example, has at times been prohibited from disguising agents as members of certain aid organizations, or as members of the clergy.
The degree of sophistication put into non-official cover stories can vary considerably. Sometimes, an agent will simply be appointed to a position in a well-established company which can provide the appropriate opportunities. Other times, entire front companies can be established in order to provide false identities for agents.
Nicholas Anderson is a real NOC who wrote an account of his service in a fictionalized autobiography (as per British law). The original non-fiction manuscript breached the UK Official Secrets Act in 2000 and appeared in a 100 banned books list published in 2003.
Michael Ross, a former Mossad officer, operated as a Mossad NOC or "combatant" as described in his memoir, The Volunteer: The Incredible True Story of an Israeli Spy on the Trail of International Terrorists, Skyhorse Publishing, September 2007, ISBN 978-1-60239-132-1.
Fictional examples are featured in the books Confessions of a Dangerous Mind, Debt of Honor, Ted Bell's Pirate, and The Eleventh Commandment; in the movies Mission: Impossible, Spy Game, The Bourne Identity, Safe House, and The Recruit; and the TV shows The Americans, Burn Notice, Spooks and Covert Affairs.