Special Service Agreement

A Special Service Agreement (SSA) is a contract modality in the United Nations system, establishing a legal relation between the Organization and the individual, where the individual is a contractor or supplier of services, rather than a staff member. This modality is often used for very short contracts, when the Organization does not wish to assume the burden of complex bureaucracy related to hiring a new staff member, and deal with complex entitlements and benefits.

Source: Wikipedia — Special Service Agreement (CC BY-SA 4.0)