The World Association for the Development of Philately (WADP) and the Universal Postal Union (UPU) jointly conceived and developed the WADP Numbering System - WNS, which was launched on 1 January 2002.

WADP Numbering System (WNS)



  • Federation Internationale de Philatelie
  • The International Federation of Stamp Dealers Associations
  • AIJP
  • Association Internationale des Editeurs de catalogues
  • Intergraf