International Mobile Satellite Organization
- 99 City Road, London EC1Y 1AX, United Kingdom
International Telecommunications Satellite Organization
- 4400 Jenifer Street NW, Suite 332, Washington, DC 20015, USA
International Trade Union Confederation
- Boulevard du Roi Albert II 5, 1210 Brussels, Belgium
Missile Technology Control Regime
- No permanent headquarters; chair-supported export control regime
Permanent Court of Arbitration
- Peace Palace, Carnegieplein 2, 2517 KJ The Hague, Netherlands
Group of 20
- No permanent headquarters; annually chaired intergovernmental forum

