Staff assessment: Staff assessment is a form of internal tax administered by the organizations. Staff assessment rates are derived from income tax rates applicable at the eight headquarters cities of the organizations in the common system (Geneva, London, Madrid, Montreal, New York, Paris, Rome, and Vienna).

Income taxes: Most member states have granted United Nations staff exemption from national income taxation on their United Nations emoluments. However, a few member States do tax the emoluments of their nationals. In such cases, the organizations reimburse the income tax to the staff member.