• ITU Member States;
• Palestine
• The United Nations;
• regional telecommunications organizations;
• intergovernmental organizations operating satellite systems;
• specialized agencies of the United Nations and the International Atomic Energy Agency;
• recognized operating agencies, scientific or industrial organizations and financial or development institutions and which are approved by the MS concerned;
• regional and other international telecommunication, standardization, financial or development organizations

In accordance with the General Rules of conferences, assemblies and meetings of the Union , invitations were sent to Member States as well as to Observer Organizations and Entities (circular-letters Nos. 83, No. 87, DM 05/1241 and DM-05/1242 refer).

Each Member State and Observer Organization and Entity may designate and register as many representatives as it deems necessary. There is no limitation on the number of representatives attending the Conference. Organizations and Entities are referred to No. 476 of the Convention and Article 7, paragraphs 1b) and 5b) of the Financial Regulations which are applicable to this Conference.