Postal Administrations

Small European Postal Administration Cooperation

http://www.sepacstamps.eu/
Collect GB Stamps Small European Postal Administration Cooperation
http://www.sepacstamps.eu/

United Nations Postal Administration

http://unstamps.un.org
Collect GB Stamps United Nations Postal Administration
http://unstamps.un.org

Universal Postal Union

http://www.upu.int/index.html
Collect GB Stamps Universal Postal Union
http://www.upu.int/index.html

World Association for the Development of Philately

http://www.wnsstamps.ch/
Collect GB Stamps World Association for the Development of Philately
http://www.wnsstamps.ch/