The United Nations system is made up of the organizations established by the Charter of the United Nations, that is, the United Nations proper, the specialized agencies provided for in Article 57 of the Charter and a number of programmes established by the General Assembly under its authority derived from Article 22 of the Charter. To this must be added the International Atomic Energy Agency (IAEA) which is not a specialized agency in the strict legal sense.

The UN System has often been characterized as a “family” each with different mandates, diverse legislative and governing bodies and historical roots. The organizations are referred to collectively as "organizations of the United Nations system" which encompasses those organizations within and outside the "United Nations Common System". The Specialized Agencies and Related Organizations maintain separate legislative and governing bodies which provide the directives for their mandates. These organizations coordinate with the broader work of the United Nations through Inter-Organizational Agreements with the General Assembly and the Economic and Social Council facilitated through the CEB.

The term "United Nations Common System" is shorthand for the common system of salaries, allowances and other conditions of service. Its origin can be traced to the relationship agreements concluded between the United Nations and the Specialized Agencies. While the wording of these agreements varies, most of them carry language to the effect that it is agreed to develop common personnel standards, methods and arrangements designed to avoid serious discrepancies in terms and conditions of employment, to avoid competition in recruitment of personnel and to facilitate the interchange of personnel. The International Civil Service Commission is the independent expert body established by the United Nations General Assembly to regulate and coordinate the conditions of service of staff in the United Nations common system while promoting and maintaining high standards in the international civil service.

Funds and Programmes

The fund and programmes (UNDP, UNICEF, UNHCR, UNRWA, UNEP, WFP, UNODC, UNCTAD, UNFPA, UN-HABITAT) were created by the United Nations to meet needs not envisaged at San Francisco, such as Palestine refugees, development assistance, food aid, or the environment. They are subordinate to the United Nations, but since they are immediately controlled by distinct inter-governmental bodies and derive most of their financial resources from other sources than the United Nations budgets, they are somewhat more akin to specialized agencies than to "subsidiary organs" such as UN commissions and committees. Moreover, as their activities are more operational and carried out at field level, they have needs dictated by an environment quite different from that of headquarters-centred administrations. The Programmes and Funds apply UN rules and regulations in the realm of administration and personnel.

Specialized Agencies

Specialized Agencies are linked to the United Nations through sections of Articles 55-65 of the United Nations Charter. They can be established by an intergovernmental agreement, subject to the approval of the General Assembly (Article 57, UN Charter) and are set up to help achieve: higher standards of living, full employment, conditions of economic and social progress and development; find solutions to international economic, social health, and related problems; international cultural and educational cooperation; and universal respect for, and observance of, human rights and fundamental freedoms for all without distinction as to race, sex, language, or religion (Article 55, UN Charter). Funds and Programmes, while not mentioned by name in the United Nations Charter, are considered subsidiary organs of the General Assembly, pursuant to Article 22 of the United Nations whereby “the General Assembly may establish such subsidiary organs as it deems necessary for the performance of its functions”.

Related Organizations

The term “Related Organization” has to be understood as a default expression, describing organizations whose cooperation agreement with the United Nations has many points in common with that of Specialized Agencies, but does not refer to Article 57 and 63 of the United Nations Charter, relevant to Specialized Agencies. Nonetheless, these organizations are part and parcel of the work of CEB.

The relationship agreement between IAEA and the UN is contained in resolution 1145 (XII) of the UN General Assembly (14 November 1957). To all intents and purposes IAEA operates like a specialized agency. The unique feature is that IAEA reports to the General Assembly and when appropriate to the Security Council as well as to ECOSOC on matter within ECOSOC’s competence. The specialized agencies report to ECOSOC.

The status of the World Trade Organization (WTO) is more complex. Neither GATT (the predecessor to WTO) nor WTO has a formal agreement with the UN. The relationship of these entities to the United Nations dates back to 1952 when Eric Wyndham White (the first Executive Secretary of GATT) and Trygve Lie, the UN Secretary-General exchange letters which took note of the “close de facto working arrangements which exist between the United Nations Secretariat and the Secretariat of the Interim Commission (GATT)”. With the creation of WTO (1 January 1995) there was a further exchange of letters underlining the cooperative nature of the relationship between the WTO Director-General (Renato Ruggiero) and UN Secretary-General (Boutros Boutros-Ghali) in October 1995 of which the UN General Assembly took note in resolution 322 (12 December 1995). The Executive Heads of IAEA and WTO are invited to meetings of the CEB like any other specialized agency head.