General Assembly Rules of Procedure (A/520/Rev.15):
Committee on Contributions
Rule 158 : The General Assembly shall appoint an expert Committee on Contributions consisting of eighteen members.
Rule 159 : The members of the Committee on Contributions, no two of whom shall be nationals of the same State, shall be selected on the basis of broad geographical representation, personal qualifications and experience and shall serve for a period of three years corresponding to three calendar years. Members shall retire by rotation and shall be eligible for reappointment. The General Assembly shall appoint the members of the Committee on Contributions at the regular session immediately preceding the expiration of the term of office of the members of, in case of vacancies, at the next session.
Rule 160 : The Committee on Contributions shall advise the General Assembly concerning the appointment , under Article 17, paragraph 2, of the Charter, of the expenses of the Organization among Members, broadly according to capacity to pay. The scale of assessments, when once fixed by the General Assembly, shall not be subject to a general revision for at least three years unless it is clear that there have been substantial changes in relative capacity to pay. The Committee shall also advise the General Assembly on the assessments to be fixed for new Members, on appeals by Members for a change of assessments and on the action to be taken with regard to the application of Article 19 of the Charter.