Article 108 provides:
Amendments to the present Charter shall come into force for all Members of the United Nations when they have been adopted by a vote of two thirds of the members of the General Assembly and ratified in accordance with their respective constitutional processes by two thirds of the Members of the United Nations, including all the permanent members of the Security Council.
Because Charter amendments require the consent of all five permanent members of the United Nations Security Council—defined in Article 23 of the Charter as "The Republic of China, France, the Union of Soviet Socialist Republics, the United Kingdom of Great Britain and Northern Ireland, and the United States"—it is impossible for other UN member states to force the permanent five to give up their Security Council 'veto power', by means of a Charter amendment. Many reformers have described this situation as a Catch-22. According to Global Policy Forum, "the P-5 are content with the present arrangements and oppose any changes that might dilute or challenge their power or expand their 'club.' China has already announced it will block permanent membership for Japan, and the United States has suggested that it will only support Council reform that commands an implausibly 'broad consensus'".
Article 109 provides for the convening of a "General Conference of the Members of the United Nations" to consider amendments. In 1955, the UN General Assembly established a committee to meet and report on this possibility annually. The committee did so until 1967. The requirement that a "proposal to call such a conference shall be placed on the agenda" of the 1955 General Assembly reflects the intent of the UN Charter's framers that the original charter would only be a provisional document, until the establishment of a more perfect union within a decade or two. Many organizations have launched lobbying efforts and petition drives in an attempt to invoke the provisions of Article 109.
According to the Commission on Global Governance's 1995 report Our Global Neighborhood, "Article 109 of the UN Charter envisaged Charter revision. A mandatory revision was one idea canvassed at San Francisco, in the context of the objections to the provision for a veto by countries that were not great powers".
The changes to the UN Charter, made by means of five amendments, were:
These amendments were adjustments to take into account increases in the UN membership, which has almost quadrupled since 1945.
Major changes to the Charter-defined structure of the UN have also been made without formal amendment of the text: