The Charter was signed on 26 June 1945 by the representatives of the 50 countries. Poland, which was not represented at the Conference, signed it later and became one of the original 51 Member States.
The Charter of the United Nations was signed on 26 June 1945, in San Francisco, at the conclusion of the United Nations Conference on International Organization, and came into force on 24 October 1945. The Statute of the International Court of Justice is an integral part of the Charter.
Amendments to Articles 23, 27 and 61 of the Charter were adopted by the General Assembly on 17 December 1963 and came into force on 31 August 1965. A further amendment to Article 61 was adopted by the General Assembly on 20 December 1971, and came into force on 24 September 1973. An amendment to Article 109, adopted by the General Assembly on 20 December 1965, came into force on 12 June 1968.
The amendment to Article 23 enlarges the membership of the Security Council from eleven to fifteen. The amended Article 27 provides that decisions of the Security Council on procedural matters shall be made by an affirmative vote of nine members (formerly seven) and on all other matters by an affirmative vote of nine members (formerly seven), including the concurring votes of the five permanent members of the Security Council.
The amendment to Article 61, which entered into force on 31 August 1965, enlarged the membership of the Economic and Social Council from eighteen to twenty-seven. The subsequent amendment to that Article, which entered into force on 24 September 1973, further increased the membership of the Council from twenty-seven to fifty-four.
The amendment to Article 109, which relates to the first paragraph of that Article, provides that a General Conference of Member States for the purpose of reviewing the Charter may be held at a date and place to be fixed by a two-thirds vote of the members of the General Assembly and by a vote of any nine members (formerly seven) of the Security Council. Paragraph 3 of Article 109, which deals with the consideration of a possible review conference during the tenth regular session of the General Assembly, has been retained in its original form in its reference to a "vote, of any seven members of the Security Council", the paragraph having been acted upon in 1955 by the General Assembly, at its tenth regular session, and by the Security Council.